Software Development AI agent skills
13,359 skills in the archive. Read a skill’s instructions or open its original repository.
Extreme Software Optimization
by @pedronauck
Profile-driven performance optimization with behavior proofs. Use when: optimize, slow, bottleneck, hotspot, profile, p95, latency, throughput, or algorithmic improvements.
Xstate
by @pedronauck
Comprehensive guide for XState v5 ecosystem including state machines, actors, @xstate/store, and TanStack Query integration. Use when implementing state machines, event-driven stores, client state management, or integrating…
Spec Peer Review
by @pedronauck
Run one requested external review of an approved spec, design doc, RFC, or detailed PRD; produce findings for user-selected incorporation. Excludes implementation reviews and automatic or looping approval gates.
Architectural Analysis
by @pedronauck
Audit architecture, dead code, duplication, type confusion, and code smells across a codebase. Excludes formatting, performance profiling, security audits, and feature-level reviews.
App Renderer Systems
by @pedronauck
Create, extend, or debug frontend domain modules organized under systems/. Covers adapters, Query hooks, local state, and public exports; excludes generic components and backend implementation.
No Workarounds
by @pedronauck
Evaluate a proposed fix that suppresses errors, diagnostics, or symptoms. Use for suspected workarounds and unavoidable external defects; not as a mandatory stage for every bug fix.
Electron Release
by @pedronauck
Expert guide for Electron production builds, code signing, notarization, auto-updates, and release workflows. Use when building, packaging, or releasing Electron applications, configuring electron-builder, setting up CI/CD…
Electron Dev
by @pedronauck
Expert guide for Electron development with Electron Vite and Electron Builder. Use when developing Electron applications, working with main/renderer processes, IPC communication, preload scripts, security configuration, native…
Zustand
by @pedronauck
Expert guide for Zustand state management patterns, store organization, and best practices. Use when implementing client state management with Zustand, creating stores, or managing shared UI state across components.
Es Toolkit
by @pedronauck
Use when implementing utility functions, array operations, object manipulation, or string operations. ALWAYS use es-toolkit instead of custom implementations or native methods.
Context7
by @pedronauck
Retrieves up-to-date documentation, API references, and code examples for any developer technology. Use this skill whenever the user asks about a specific library, framework, SDK, CLI tool, or cloud service — even for well-known…
Deslop
by @pedronauck
Review a changed diff for accidental complexity or generated-code noise. Use when requested or when the diff shows those symptoms; an equivalent review of unchanged inputs need not repeat.
Enterprise Ai Scenario Map
by @MetaInFLow
企业AI场景地图生成报告工具。通过 web-search 深度调研企业信息,按照V2.1标准模板生成结构化AI应用场景地图报告,包含企业画像、业务诊断、行业实践、AI场景全量表、实施路径等完整内容。
Easyeda Agent
by @zhoushoujianwork
通过本地 easyeda CLI、daemon 和连接器操作嘉立创EDA专业版(EasyEDA Pro):用可迁移样例和参数化数据构建或修复原理图、布局布线 PCB,并回读连接、几何、DRC 与保存结果。适用于已有工程操作及数据驱动电路设计。
1688 Item Selection
by @next-1688
1688 商家重点品圈选 —— 基于多维度商品评分智能识别值得重点运营的商品或搜索商品。 工具能力:五维度评分(销售贡献、流量效率、成长潜力、营销ROI、商品健康度),商品分层(S/A/B/C级),搜索商品。 触发词:重点品查看、圈选重点品、圈选运营商品、今日运营重点、选品、推荐商品、商品分层、商品优先级、搜索商品。
Knowledge Absorber
by @YuJunZhiXue
深度解析链接、文档或代码,生成”全能导师级”的教学笔记(零基础直达精通)。具备”真理锚定”校验能力,自动识别幻觉与过时信息。支持国学风格渲染,自动清理广告和无用内容。
Easyeda Repo Lookup
by @zhoushoujianwork
只读查询 easyeda-agent 仓库的工具能力、实现、参数化样例与验证证据,适合在其他项目中复用 EDA 自动化经验。 Search the linked easyeda-agent checkout for capabilities, implementation, examples, and evidence; does not operate an EDA document.
Easyeda Repo Maintain
by @zhoushoujianwork
维护 easyeda-agent 仓库的 Skill、CLI、daemon、connector 与文档,补回可复用经验并组织验证和 Git 贡献。 Develop and contribute to the linked automation repository; use easyeda-agent for circuit design operations.
Workflow
by @waynesutton
Project workflow for PRDs, task tracking, changelog sync, and documentation updates. Use for any non-trivial task that spans multiple steps, touches several files, changes architecture, or needs project tracking updates. Also…
Real Time Backend
by @waynesutton
Build reactive, type-safe, production-grade backends. ALWAYS use this skill when the user asks to build, plan, design, or implement backend features, APIs, data models, server logic, database schemas, web apps, full stack apps,…
React Effect Decision
by @waynesutton
Combine React's official "You Might Not Need an Effect" guidance with this project's stricter no direct useEffect stance. Use when writing, reviewing, or refactoring React components that might reach for useEffect, derived…
Dev
by @waynesutton
Full-stack Convex development guidelines covering React, Vite, TypeScript, mutations, auth, design system, and documentation practices. Use when building features, writing Convex functions, or making code changes in this project.
Memory
by @ovh
Save, organize, and curate persistent memories (MEMORY.md index plus topic files) across sessions. Load before writing detailed notes, topic files, or when asked to remember context that should outlive this session.
Convex Setup Auth
by @waynesutton
Set up Convex authentication with proper user management, identity mapping, and access control patterns. Use when implementing auth flows, setting up OAuth providers, or adding role-based access control.
Write
by @waynesutton
Writing style guide for technical content, social media, blog posts, READMEs, git commits, and developer documentation. Optimized to avoid AI detection patterns. Use when writing any content beyond code.
Help
by @waynesutton
Reflection-first problem solving methodology for Convex development. Use before implementing any solution to ensure proper root cause analysis, 98% code confidence, and minimal change scope.
Gitrules
by @waynesutton
Critical Git safety rules to prevent destructive operations. Use whenever performing git operations, reverting changes, or managing commits. Prevents accidental loss of work.
Schema Builder
by @waynesutton
Design and generate Convex database schemas with proper validation, indexes, and relationships. Use when creating schema.ts or modifying table definitions.
Function Creator
by @waynesutton
Create Convex queries, mutations, and actions with proper validation, authentication, and error handling. Use when implementing new API endpoints.
Repo Analysis
by @ovh
Analyze uncommitted changes in the repository, group them into logical commits, and determine the appropriate version bump
Refactoring
by @ovh
Restructure existing code to improve readability, maintainability, and performance without changing behavior
Code Review
by @ovh
Review code changes in the current git branch, identify bugs, style issues, and suggest improvements
Release
by @ovh
Prepare and publish a new release of the SHAI project, including version bumps and tagging
Debugging
by @ovh
Systematically diagnose and fix bugs using logs, stack traces, and targeted experiments
Git Workflow
by @ovh
Manage git branches, commits, rebases, and pull requests following project conventions
Rust Lint
by @ovh
Check and fix Rust build warnings and clippy warnings across the project
News Extractor
by @NanmiCoder
新闻站点内容提取。支持 12 个平台:微信公众号、今日头条、网易新闻、搜狐新闻、腾讯新闻、BBC News、CNN News、Twitter/X、Lenny's Newsletter、Naver Blog、Detik News、Quora。当用户需要提取新闻内容、抓取公众号文章、爬取新闻、或获取新闻JSON/Markdown时激活。
Ray
by @Railly
Generate code screenshots via ray.tinte.dev API. Use when user asks for code screenshots, code images, code snippets as images, or says "ray". Calls POST https://ray.tinte.dev/api/v1/screenshot and saves the PNG result.
Sage Wiki
by @xoai
Reference skill for sage-wiki — local-first knowledge graph with MCP server, REST API, compiled wiki, and Obsidian-compatible output.
Sage Wiki Integrate
by @xoai
Pipeline skill that wires sage-wiki into an existing project — detects language, installs the client, runs a smoke test, and reports.
Bio Causal Genomics Fine Mapping
by @PKU-YuanGroup
Resolves GWAS associations to candidate causal variants and credible sets via SuSiE, susie_rss, FINEMAP, CAVIAR, DAP-G, PAINTOR, PolyFun, SuSiEx, MultiSuSiE, and FOCUS. Use when narrowing a GWAS lead SNP to a 95 percent credible…
Bio Chipseq Differential Binding
by @PKU-YuanGroup
Identifies differentially bound ChIP-seq regions between conditions using DiffBind, csaw (sliding windows), DESeq2/edgeR/PyDESeq2 on count matrices, NormR (control-aware), or MAnorm2. Distinguishes three distinct normalization…
Bio Alignment Structural
by @PKU-YuanGroup
Align protein structures using Foldseek 3Di, TM-align, US-align, DALI, or Foldmason for structural MSA. Predict, score, and superpose backbone coordinates when sequence identity is below the twilight zone or remote-homology…
Bio Alignment Trimming
by @PKU-YuanGroup
Trim multiple sequence alignments using ClipKIT, trimAl, BMGE, Divvier, or HMMcleaner with mode selection guidance per downstream goal. Use when removing unreliable columns or contaminating residues before phylogenetic…
Bio Chipseq Qc
by @PKU-YuanGroup
Assesses ChIP-seq quality across antibody specificity, fragmentation, enrichment, replicate concordance, and library complexity. Computes FRiP, NSC/RSC (phantompeakqualtools), library complexity (NRF/PBC1/PBC2), deepTools…
Bio Causal Genomics Effector Gene Prioritization
by @PKU-YuanGroup
Maps GWAS-implicated loci to candidate effector (causal) genes by integrating variant-to-gene (V2G) features via Open Targets L2G (Mountjoy 2021), MAGMA gene-based association (de Leeuw 2015), FUMA SNP2GENE, cS2G combined…
Bio Causal Genomics Heritability Partitioning
by @PKU-YuanGroup
Estimates SNP heritability and partitions it across functional annotations, cell types, and loci from GWAS summary statistics or individual-level genotypes. Implements LDSC, stratified LDSC with the baseline-LD model, Finucane…
Bio Causal Genomics Genomic Sem
by @PKU-YuanGroup
Fits structural equation models to GWAS summary statistics using GenomicSEM (Grotzinger 2019), including common-factor models, confirmatory factor models, ESEM, common-factor GWAS with Q_SNP heterogeneity, multivariate Wald…
Bio Chipseq Peak Annotation
by @PKU-YuanGroup
Annotates ChIP-seq peaks to genomic features, nearest genes, ENCODE candidate cis-regulatory elements (cCREs), and regulatory domains. Uses ChIPseeker (R), HOMER annotatePeaks.pl (CLI), pyranges (Python), GREAT/rGREAT…
Bio Causal Genomics Transcriptome Wide Association
by @PKU-YuanGroup
Performs gene-level association from GWAS summary statistics via genetically predicted tissue expression using FUSION, PrediXcan, S-PrediXcan, S-MultiXcan, UTMOST, MOSTWAS, kTWAS, EpiXcan, TIGAR-V2, and probabilistic…
Bio Chipseq Super Enhancers
by @PKU-YuanGroup
Identifies super-enhancers from H3K27ac, MED1, or BRD4 ChIP-seq using ROSE, ROSE2, LILY, HOMER -style super, and ENCODE dELS cross-referencing. Handles peak stitching parameters, ranking choices, hockey-stick inflection, marker…
Bio Differential Splicing
by @PKU-YuanGroup
Detects differential alternative splicing between conditions using rMATS-turbo (binomial LRT on junction counts), leafcutter (Dirichlet-multinomial GLM on intron clusters), MAJIQ V3 deltapsi/HET (Bayesian posterior on LSVs),…
Bio Alignment Multiple
by @PKU-YuanGroup
Perform multiple sequence alignment using MAFFT, MUSCLE5, ClustalOmega, or T-Coffee. Guides tool and algorithm selection based on dataset size, sequence divergence, and downstream application. Use when aligning three or more…
Bio Alignment Validation
by @PKU-YuanGroup
Validate alignment quality with insert size distribution, proper pairing rates, GC bias, strand balance, and other post-alignment metrics. Use when verifying alignment data quality before variant calling or quantification.
Bio Sam Bam Basics
by @PKU-YuanGroup
View, convert, and understand SAM/BAM/CRAM alignment files using samtools and pysam. Use when inspecting alignments, converting between formats, or understanding alignment file structure.
Bio Single Cell Splicing
by @PKU-YuanGroup
Analyzes alternative splicing at single-cell resolution. The first decision is library chemistry — 10X 3' is fundamentally limited (RT primes from poly-A, R2 falls in 3' UTR, <0.1 junction read per cell per AS event).…
Bio Splice Variant Prediction
by @PKU-YuanGroup
Predicts whether a DNA variant alters mRNA splicing using sequence-based deep-learning tools — SpliceAI (10kb context dilated CNN, clinical default), Pangolin (multi-tissue), MMSplice (modular per-region CNN with calibrated…
Bio Chipseq Chip Deep Learning
by @PKU-YuanGroup
Trains and applies base-resolution deep learning models on ChIP-seq / ChIP-nexus / CUT&RUN data. Uses BPNet (Avsec 2021 Nat Genet 53:354; soft motif syntax from ChIP-nexus), chromBPNet (Pampari A et al 2024 bioRxiv;…
Bio Splicing Quantification
by @PKU-YuanGroup
Quantifies alternative splicing as PSI (percent spliced in) from RNA-seq using rMATS-turbo (BAM-based event), SUPPA2 (TPM-based event), MAJIQ V3 (LSV-based Bayesian), leafcutter (annotation-free intron clusters), VAST-TOOLS…
Bio Chipseq Allele Specific Binding
by @PKU-YuanGroup
Detects allele-specific transcription factor or histone modification binding from heterozygous-variant ChIP-seq using WASP (reference-bias filter; mandatory upstream), RASQUAL (joint QTL + bias-corrected testing), BaalChIP…
Bio Isoform Switching
by @PKU-YuanGroup
Analyzes differential transcript usage (DTU) and isoform switches with functional consequence prediction (NMD via 50nt rule, ORF disruption, protein domain loss/gain, signal peptide changes, IDR alterations, coding-potential…
Bio Clinical Biostatistics Bayesian Trials
by @PKU-YuanGroup
Designs Bayesian clinical trials including Phase I dose-finding (BOIN, CRM, EWOC, mTPI-2), meta-analytic-predictive (MAP) priors with robust mixtures for external data borrowing, EXNEX for basket trials, hierarchical models for…
Bio Pharmacophore Modeling
by @PKU-YuanGroup
Builds and applies 3D pharmacophore models using RDKit Pharm3D, the apo2ph4 receptor-based workflow (Heider et al. 2023), Pharmer / Pharmit for search, and PharmacoForge for protein-pocket-conditioned pharmacophore generation…
Bio Covalent Design
by @PKU-YuanGroup
Designs covalent inhibitors and warheads targeting cysteine, lysine, serine, threonine, tyrosine, and aspartate residues, with explicit handling of warhead reactivity (acrylamide, chloroacetamide, vinyl sulfone, sulfonyl…
Bio Clinical Biostatistics Multiplicity Graphical
by @PKU-YuanGroup
Implements multiplicity control for confirmatory clinical trials using graphical procedures (Bretz-Maurer-Hommel), gatekeeping (parallel, serial, mixed), Hochberg/Hommel/Holm with PRDS, and the closed-testing principle…
Bio Molecular Standardization
by @PKU-YuanGroup
Standardizes molecular structures using the ChEMBL structure pipeline for normalization and parent selection plus RDKit rdMolStandardize for explicit custom steps such as tautomer canonicalization, salt/solvent stripping, charge…
Bio Clinical Biostatistics Adaptive Designs
by @PKU-YuanGroup
Designs adaptive clinical trials including group-sequential (O'Brien-Fleming, Pocock, Lan-DeMets spending), sample-size re-estimation (blinded Friede-Kieser, unblinded Cui-Hung-Wang, Mehta-Pocock promising zone), seamless Phase…
Bio Free Energy Calculations
by @PKU-YuanGroup
Performs alchemical free-energy calculations including relative binding free energy (RBFE / FEP+) and absolute binding free energy (ABFE) via OpenFE, FEP+, GROMACS, AMBER pmemd, and OpenMM with explicit lambda scheduling,…
Bio Chipseq Peak Calling
by @PKU-YuanGroup
Calls ChIP-seq peaks with MACS3, MACS2, HOMER, or SPP across narrow (TF) and broad (histone) modes. Handles input control matching, fragment-size modeling vs --nomodel, effective genome size, ENCODE-style IDR vs naive overlap,…
Bio Clinical Databases Acmg Classification
by @PKU-YuanGroup
Applies ACMG/AMP 2015 framework with ClinGen SVI specifications, Tavtigian 2018/2020 Bayesian point system, Abou Tayoun 2018 PVS1 decision tree, Pejaver 2022 and Bergquist 2025 calibrated PP3/BP4 thresholds for…
Bio Conformer Generation
by @PKU-YuanGroup
Generates 3D conformer ensembles using RDKit ETKDGv3 with knowledge-enhanced distance geometry, MMFF94/UFF force-field optimization, CREST + GFN2-xTB semi-empirical refinement, and macrocycle-aware torsion preferences. Provides…
Bio Shape Similarity
by @PKU-YuanGroup
Performs 3D shape-based similarity searching using ROCS (OpenEye), USRCAT (ultra-fast), Open3DAlign (RDKit), ESPSim (electrostatic), and ShaEP with explicit handling of Tanimoto-Combo (shape + color), shape vs ECFP4…
Bio Clinical Biostatistics Missing Data
by @PKU-YuanGroup
Implements missing-data sensitivity analyses for confirmatory clinical trials including MMRM under MAR (with Kenward-Roger correction), reference-based multiple imputation (J2R, CR, CIR, LMCF per Carpenter-Roger 2013), Permutt…
Bio Reaction Enumeration
by @PKU-YuanGroup
Enumerates virtual chemical libraries via reaction SMARTS transformations using RDKit and reaction templates, with explicit handling of atom mapping, RDChiral template extraction, product validation, RECAP/BRICS fragmentation,…
Bio Retrosynthesis
by @PKU-YuanGroup
Performs retrosynthetic planning using AiZynthFinder (template-based MCTS), maintained or version-pinned template-free models, ASKCOS, and emerging RetroSynFormer with explicit handling of route scoring, configurable MCTS…
Bio Similarity Searching
by @PKU-YuanGroup
Performs molecular similarity searching using Tanimoto, Tversky, Dice, and cosine coefficients on bit/count fingerprints with explicit choice rules for symmetric vs asymmetric measures, scaffold-hopping vs lead-optimization…
Bio Clinical Biostatistics Survival Analysis
by @PKU-YuanGroup
Performs time-to-event analysis for clinical trials including Cox proportional hazards regression with PH diagnostics, restricted mean survival time (RMST) under non-PH, competing risks via Fine-Gray vs cause-specific Cox,…
Bio Clinical Biostatistics Power Sample Size
by @PKU-YuanGroup
Computes sample size and power for clinical trials including continuous, binary, and time-to-event endpoints; superiority, non-inferiority, and equivalence designs; FDA 2016 non-inferiority margin selection with M1/M2 framework;…
Bio Atac Seq Enhancer Gene Linking
by @PKU-YuanGroup
Predict enhancer-gene regulatory connections from ATAC-seq using ABC, ENCODE-rE2G, HiChIP, or Cicero. Use when linking distal enhancers to target genes, choosing between contact-aware (ABC, ENCODE-rE2G), accessibility-only…
Bio Atac Seq Consensus Peakset
by @PKU-YuanGroup
Build a differential-ready consensus peakset from per-replicate ATAC-seq peaks using iterative overlap removal, fixed-width re-centering, and majority-rule overlap. Use when generating a stable peak coordinate system for…
Bio Atac Seq Single Cell Atac
by @PKU-YuanGroup
Process and analyze single-cell ATAC-seq data with Signac, ArchR, SnapATAC2, or Cell Ranger ATAC. Use when handling 10X scATAC or 10X Multiome (paired RNA+ATAC) data, performing per-cell QC, choosing between…
Bio Molecular Io
by @PKU-YuanGroup
Reads, writes, and converts molecular file formats (SMILES, InChI, SDF V2000/V3000, MOL2, PDB, and BinaryCIF) using RDKit and Open Babel with rigorous handling of aromaticity perception, stereochemistry, implicit/explicit…
Impacting Prs
by @LedgerHQ
Find which open PRs are impacted by a migration/sunset/refactor and notify their authors — blocking review when the old path is already gone from develop, heads-up comment when it is only deprecated or its removal is still in…
Bio Atac Seq Co Accessibility
by @PKU-YuanGroup
Infer cis-regulatory connections (peak-to-peak co-accessibility) from scATAC-seq using Cicero, ArchR getCoAccessibility, or SCENIC+. Use when linking enhancer accessibility to promoter accessibility, identifying enhancer-gene…
Bio Substructure Search
by @PKU-YuanGroup
Searches molecular libraries for substructure matches using SMARTS patterns with explicit handling of recursive SMARTS, ring membership, aromaticity dialect, vector binding, atom map indices, and reactive/PAINS/REOS/Brenk filter…
Bio Atac Seq Allele Specific Accessibility
by @PKU-YuanGroup
Detect allele-specific chromatin accessibility from ATAC-seq using WASP, GATK ASEReadCounter, or RASQUAL. Use when mapping cis-regulatory genetic variants from heterozygous SNPs, separating cis from trans regulation, building…
Bio Atac Seq Nucleosome Positioning
by @PKU-YuanGroup
Map nucleosome center positions, occupancy, and fuzziness from ATAC-seq fragment-size patterns using NucleoATAC, ATACseqQC, DANPOS3, or scprinter. Use when characterizing nucleosome organization at promoters and enhancers,…
Bio Atac Seq Footprinting
by @PKU-YuanGroup
Detect transcription factor binding footprints in ATAC-seq using TOBIAS, HINT-ATAC, Wellington, or scprinter. Use when identifying bound TF sites within accessible regions, correcting Tn5 insertion bias before footprinting,…
Bio Clinical Databases Clinvar Lookup
by @PKU-YuanGroup
Queries ClinVar for variant pathogenicity classifications, ClinGen VCEP curations, and somatic-vs-germline interpretations via REST API, weekly VCF, or bulk XML. Use when determining clinical significance, triangulating…
Bio Clinical Databases Dbsnp Queries
by @PKU-YuanGroup
Resolves rsIDs, navigates RsMergeArch/SNPHistory merge chains, and converts between rsID, SPDI, HGVS, and VCF representations using the dbSNP Build 156 JSON architecture. Use when normalizing variant identifiers, joining variant…
Remove Feature Flag
by @LedgerHQ
Remove a Ledger Wallet feature flag while preserving its resolved production behavior, then validate, create a draft PR, and watch CI to green. Invoke only through /remove-feature-flag; this command may stash local work, push a…
Bio Alignment Amplicon Clipping
by @PKU-YuanGroup
Trim PCR primers from aligned reads in amplicon-panel BAMs using samtools ampliconclip. Use when processing SARS-CoV-2 ARTIC, hereditary cancer panels, ctDNA hot-spot panels, or any amplicon assay where primer-derived bases…
Bio Alignment Filtering
by @PKU-YuanGroup
Filter alignments by flags, mapping quality, and regions using samtools view and pysam. Use when extracting specific reads, removing low-quality alignments, or subsetting to target regions.
Bio Pileup Generation
by @PKU-YuanGroup
Generate pileup data for variant calling using samtools mpileup and pysam. Use when preparing data for variant calling, analyzing per-position read data, or calculating allele frequencies.
Bio Reference Operations
by @PKU-YuanGroup
Generate consensus sequences and manage reference files using samtools. Use when creating consensus from alignments, indexing references, or creating sequence dictionaries.
Bio Duplicate Handling
by @PKU-YuanGroup
Mark and remove PCR/optical duplicates using samtools fixmate and markdup. Use when preparing alignments for variant calling or when duplicate reads would bias analysis.
Bio Alignment Indexing
by @PKU-YuanGroup
Create and use BAI/CSI indices for BAM/CRAM files using samtools and pysam. Use when enabling random access to alignment files or fetching specific genomic regions.
Bio Alignment Sorting
by @PKU-YuanGroup
Sort alignment files by coordinate or read name using samtools and pysam. Use when preparing BAM files for indexing, variant calling, or paired-end analysis.
Ledger Wallet Cli
by @LedgerHQ
Official Ledger wallet-cli - USB-based CLI for Ledger hardware wallet flows (account discover, receive, balances, operations, send, swap quote/execute/status, genuine-check, assets token / token-by-id), the Ledger Key Ring (ring…
Debug Rn Native Crash
by @LedgerHQ
Investigate native React Native crashes (Fabric/Hermes/iOS) in ledger-live-mobile when JS error logs are missing or unhelpful. Use when the app dies silently, throws an NSException on iOS, or shows only a native stack trace.