The short version
Three phone-based sleep trackers across three platform-positioning angles. Platform decides; secondary factors are customisation depth (Sleep as Android), Apple Watch integration (AutoSleep), or cross-platform polish (Sleep Cycle).
When Sleep Cycle is the right pick
If you want a polished tracker that works equally on iPhone and Android — clean UX, smart alarm, decade-old track record, deeper wind-down content — Sleep Cycle is the right shape. Most users land here.
When Sleep as Android is the right pick
If you are Android-only and value deep customisation — Tasker integration, smart-alarm automation, multiple tracking method options — Sleep as Android is the right shape. The plugin ecosystem alone justifies the pick for power users.
When AutoSleep is the right pick
If you are an iPhone user with an Apple Watch and want native HealthKit-integrated automatic sleep tracking with no smart-alarm gimmickry, AutoSleep is the right shape. Apple Watch wrist sensors give richer sleep-stage data than phone-only options.