Sun Day Tracker vs The90 Gem
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Sun Day Tracker
Monitor your daily vitamin D absorption from sunlight exposure. This straightforward application helps you keep track of your sun-related vitamin D intake.
- Track daily vitamin D intake
- Sunlight exposure monitoring
- Simple interface
- Daily tracking
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A simple app to track you daily vitamin D intake from the sun.
The90 Gem
This jewelry-inspired sensor tracks your skin's real-time UV exposure. It helps you protect against aging and harness the sun's health benefits.
- Real-time UV tracking
- Skin exposure monitoring
- Aging protection
- Sun health benefits
- Jewelry-inspired design
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The jewelry-inspired UV sensor that tracks what your skin actually experiences, so you can protect how you age while harnessing the health benefits of the sun.
Screenshots
Verdict
The clearest difference is rating: Sun Day Tracker at 4.6 against The90 Gem's 4.3. Sun Day Tracker also leads on ratings volume (26 vs 7). The90 Gem's advantage is iOS requirement (15.0 vs 17.0). On price, review sentiment, update cadence and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Sun Day Tracker holds the better App Store score, 4.6 against 4.3. Both are backed by a comparable volume of ratings — 26 and 7 respectively. Written reviews point the same way: 83% of Sun Day Tracker's written reviews are positive against 80% of The90 Gem's.
Sun Day Tracker ships an update monthly, The90 Gem every 2 weeks. The most recent releases landed on October 17, 2026 and October 5, 2026 respectively.
| Parameter | Sun Day Tracker | The90 Gem |
|---|---|---|
| Price | Free | Free |
| Rating | 4.6 (26 ratings) — better | 4.3 (7 ratings) |
| Positive reviews | 83.3% of reviews — better | 80.0% of reviews |
| Number of ratings | 26 — better | 7 |
| Update frequency | Monthly | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone | iPhone, iPod — better |
| Requires iOS | 17.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 96 MB |
| Age rating | 4+ | 4+ |
| Developer | permissionless tech, llc | The90, Inc. |
Customer experience
Sun Day Tracker
The90 Gem
In-app purchases
Sun Day Tracker
No in-app purchases
The90 Gem
No in-app purchases
