Watt vs SunSync
Price, ratings, monetisation and update history for both apps, side by side โ with what reviewers say about each.
Watt
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Stop guessing when youโll feel sharp. Watt predicts your energy rhythm for the day and turns it into a plan: focus windows, lighter moments, and recovery cues. Set your sleep schedule and chronotype, log sleep quality, and add events like coffee or workouts โ then use your forecast to decide what to tackle next. Highlights - Daily energy forecast (detailed + compact) - Sleep quality check-in - Event logging that updates your insights - Simple settings for your personal rhythm Plan less. Flow more.
SunSync
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Always tired, waking groggy, or struggling to fall asleep? The cause might be simpler than you think โ your morning light routine. SunSync syncs your day to the sun. Track sunlight exposure, estimate your vitamin D intake, and get personalized circadian rhythm guidance โ all based on your real location and habits. Your body clock controls your sleep, energy, mood, and focus. SunSync helps you work with it โ not against it. With SunSync you can: - Track sunlight exposure and daily light habits โ know when you've hit your target - Estimate vitamin D from sun exposure based on your skin type and location - Log supplements and monitor your total daily intake - Follow personalized circadian recommendations for your schedule - Discover your best sunlight windows โ and when to avoid the UV index - Build routines to improve sleep and melatonin production naturally - Set smart reminders for sunrise, sunset, and wind-down time - Add a home screen widget โ see your vitamin D window at a glance, without opening the app - View history and long-term trends to see your progress Built for the biohacking community โ and anyone who just wants to feel better. Whether you're optimizing for performance or simply tired of being tired, SunSync gives you the sunlight data your wellness routine has been missing. Vitamin D tracking, body clock alignment, supplement logging, and a home screen widget showing your vitamin D window โ in one app. Disclaimer: SunSync provides estimates and general wellness guidance. It is not a medical device and does not replace professional medical advice. Terms: https://martarodriguezm.github.io/SunSyncLegal/terms.html Privacy Policy: https://martarodriguezm.github.io/SunSyncLegal/privacy.html
Screenshots
Verdict
The clearest difference is in-app purchases: Watt at none against SunSync's 2. Watt also leads on update cadence (every 10 days vs every 3 weeks) and iOS requirement (12.0 vs 17.6). On price, ads and device support there is nothing between them.
Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS
Both are free to download. SunSync sells 2 in-app purchases, starting at $1.99 per year. Watt asks for nothing beyond the download.
Watt ships an update every 10 days, SunSync every 3 weeks. The most recent releases landed on November 9, 2026 and November 5, 2026 respectively.
| Parameter | Watt | SunSync |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 10 days โ better | Every 3 weeks |
| Ads | No | No |
| In-app purchases | No โ better | Yes |
| Devices | iPhone, iPod โ better | iPhone |
| Requires iOS | 12.0 โ better | 17.6 |
| Further details โ not scored | ||
| Size | 82 MB | 25 MB |
| Age rating | 4+ | 4+ |
| Developer | Adrian Veliman | Marta Rodriguez |
In-app purchases
Watt
No in-app purchases
SunSync
- Year3 Days trial$1.991 Year
- Lifetime$2.99









