Mobile App Stability Metrics: Crash-Free Users, ANRs & Startup Time
Crash-free users and sessions, crashes per 1,000 sessions by version, ANR and freeze rates, p50/p90 cold start, crash-cluster Pareto, staged-rollout halt rules, regression z-tests and a stability dashboard: 8 labs on one fictional app's releases.
The first lesson is free — no account needed.
About this course
A mobile app stability metrics course that follows the releases of one fictional app, Ridgeway, through the numbers mobile teams watch, for mobile developers, QA and release managers and product managers. You calculate crash-free users and crash-free sessions per day and per week, compare releases on crashes per 1,000 sessions, measure the ANR and freeze rate by device segment, compute p50 and p90 cold and warm start times against a budget, rank crash clusters on a Pareto chart, apply a halt rule to a staged rollout day by day, test whether a hotfix is really worse with a two-proportion z-test and build a weekly stability dashboard with budgets and red flags. Thresholds are illustrative and platform metrics are described in general terms, no affiliation with Apple, Google or any crash-reporting vendor. The first lab is free.
Lessons
- Crash-Free Users & Crash-Free SessionsFree
- Crash Rate per 1,000 Sessions by Version Pro
- ANR & Freeze Rate by Device Segment Pro
- Startup Time Percentiles: p50 & p90 Cold Start Pro
- Top Crash Clusters: the Pareto Chart Pro
- Staged Rollout: Continue, Wait or Halt Pro
- Regression Detection: Is the New Version Really Worse? Pro
- The Stability Dashboard: Budgets, Status & Red Flags Pro