AutoSleep vs Kasi

AutoSleep is a sleep-tracking app for Apple Watch and iPhone that records sleep automatically in the background, without requiring the user to start or stop a session. It uses heart rate, motion, and (where available) blood oxygen and wrist temperature data to estimate sleep stages, sleep quality, and a running sleep debt total called the sleep bank. The app integrates with Apple Health and HomeKit, offers a smart alarm that wakes users during a lighter sleep phase, and includes an add-on companion app, AutoSnore, for snore detection. It is sold as a single one-time purchase on the App Store rather than a subscription, and processes data on-device rather than through a cloud account.

Kasi is a running coaching app that delivers real-time audio coaching during a workout, rather than just handing runners a static plan to follow alone. Users can choose an AI-powered coach or a remote human coach who observes biometric data live and speaks instructions into the runner's ear as the workout unfolds, aiming to teach technique and pacing in the moment rather than only after the fact. Runners enter a recent race time and the app calculates target paces for different workout types, then adjusts guidance in real time. Training programs cover distances from 5K through marathon, along with menstrual-cycle-aware training and runner-specific strength work. The brand name comes from the Swahili word for speed.

• One-time purchase price with no ongoing subscription fees
• Fully automatic tracking that does not require remembering to start or stop a sleep session
• Detailed metrics including sleep stages, SpO2, respiration rate, and wrist temperature on supported hardware
• On-device processing with no account or login required for basic use

• Real-time in-ear coaching is a distinct approach versus static plan apps
• Option to use an actual remote human coach, not just AI
• Training plans cover a full range of distances
• Free trial available before committing

• Requires an Apple Watch for automatic tracking; iPhone-only use is far more limited
• Advanced metrics like SpO2 and respiration depend on specific newer Apple Watch models
• Interface and terminology (sleep bank, sleep debt) have a learning curve for new users

• Subscription cost adds up compared to free running trackers
• Human coach tier is priced separately and higher
• Newer entrant competing against more established running-coach apps
• Android availability isn't clearly confirmed on the homepage