EndureIndex vs Sleep Tracker
Price, ratings, monetisation and update history for both apps, side by side ā with what reviewers say about each.
EndureIndex
Read full descriptionHide full description
Ready to train ā or is recovery the smarter choice today? EndureIndex helps you better understand your daily readiness and plan your training more consciously. The app uses data from Apple Health and turns it into clear signals for readiness, training load, recovery and endurance development. This helps you see more clearly whether your body is ready for training, whether light movement would be a better option, or whether you should give your recovery more space. What EndureIndex offers: ⢠Readiness Score for your current daily condition ⢠Endurance Score for your endurance development ⢠Training load, recovery and trends at a glance ⢠Analysis of HRV, resting heart rate, sleep, steps and workouts ⢠Weather and environmental load, where available ⢠Clear insights instead of raw data only ⢠Goal focus for fitness, fat loss, weight maintenance, more energy, consistency and movement ⢠Apple Watch app and widgets ⢠Support for English and German Why EndureIndex? Not every day is the same. Sometimes your body is ready for an intense workout, sometimes light movement or recovery is the smarter choice. EndureIndex helps you better understand important signals from Apple Health and use them to make more conscious decisions about training and recovery. EndureIndex Pro With EndureIndex Pro, you get advanced analyses, longer trend histories, deeper insights into training load and recovery, goal evaluations, correlations and additional premium features. Privacy EndureIndex uses Apple Health data only with your permission. Your data stays on your device and is not used for tracking or advertising. Location data is only used with your permission to include weather-related load factors. Disclaimer EndureIndex is not a medical app and does not replace medical advice. The analyses are intended for personal orientation around training, recovery and fitness. Privacy Policy: https://danilo-krautz.de/privacy-endureindex/ Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Sleep Tracker
Read full descriptionHide full description
Understand your signals. Shape your day around them. Cernidia helps you make sense of your sleep, recovery and daily energy, so everyday choices about rest, movement and focus have more context. See the bigger picture behind your numbers and notice patterns over time. No ads, subscriptions or in-app purchases. No Cernidia account needed. UNDERSTAND YOUR SIGNALS ⢠Review your sleep and your next planned sleep window. ⢠Follow your daily energy estimate and recovery in your personal context. ⢠Explore breathing-rate trends, blood-oxygen readings and heart-rate zones when suitable data is available. ⢠Add a quick check-in to record how you feel. CONNECT YOUR WEARABLES Use Apple Health with Apple Watch, or connect an existing WHOOP account. WHOOP Recovery, Sleep, Strain and Workouts are labelled separately. Connections are optional, and Cernidia remains usable without a wearable. PUT INSIGHTS INTO YOUR DAY Give tasks, routines and recovery time a place in your day. Optional calendar access helps your plans fit around real commitments. The Apple Watch companion shows your current and next activity, lets you record an energy check-in and adds heart-rate context to workouts you start. CHOOSE YOUR WAKE-UP WINDOW Smart Wake lets you choose a wake-up window and uses previously recorded sleep phases to estimate a wake time. Your latest wake time serves as a backup. Alarm or notification permissions are needed for alerts; Smart Wake does not detect your current sleep stage in real time. PRIVATE AND OPTIONAL Your health summaries, check-ins and plans stay on your devices. Cernidia has no app-data cloud sync, product analytics, advertising or cross-app tracking. The optional WHOOP connection uses an online authorization service. WHOOP health records are fetched directly to your iPhone and stored locally. WHAT TO EXPECT Personal comparisons need enough readable history. Missing data stays unknown. Features depend on your device, permissions and available records. Apple Watch and WHOOP devices are sold separately; WHOOP also requires its own membership. Cernidia supports general wellness and everyday decisions. It does not diagnose conditions or provide medical treatment recommendations.
Screenshots
Verdict
The clearest difference is in-app purchases: Sleep Tracker at none against EndureIndex's 2. Sleep Tracker also leads on update cadence (every 6 days vs every 3 weeks) and iOS requirement (18.0 vs 26.0). On price, ads and device support there is nothing between them.
Scored on Price Ā· Rating Ā· Positive reviews Ā· Number of ratings Ā· Update frequency Ā· Ads Ā· In-app purchases Ā· Monetization Ā· Best chart rank Ā· Devices Ā· Requires iOS
Both are free to download. EndureIndex sells 2 in-app purchases, starting at $1.99 per month. Sleep Tracker asks for nothing beyond the download.
EndureIndex ships an update every 3 weeks, Sleep Tracker every 6 days. The most recent releases landed on October 24, 2026 and October 29, 2026 respectively.
| Parameter | EndureIndex | Sleep Tracker |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 3 weeks | Every 6 days ā better |
| Ads | No | No |
| In-app purchases | Yes | No ā better |
| Devices | iPhone, Apple Watch | iPhone, Apple Watch |
| Requires iOS | 26.0 | 18.0 ā better |
| Further details ā not scored | ||
| Size | 8 MB | 24 MB |
| Age rating | 4+ | 4+ |
| Developer | Danilo Krautz | Sven Kraln |
In-app purchases
EndureIndex
- EndureIndex Pro Monthly$1.991 Month
- EndureIndex Pro Yearly7 Days trial$14.991 Year
Sleep Tracker
No in-app purchases
Questions
Is EndureIndex free?
Is Sleep Tracker free?
Do EndureIndex or Sleep Tracker have ads?
Which is updated more often, EndureIndex or Sleep Tracker?
Other comparisons















