# Thyroid Tracker vs Soln

The clearest difference is update cadence: Thyroid Tracker at every 4 days against Soln's every 3 weeks. Thyroid Tracker also leads on iOS requirement (15.6 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Thyroid Tracker sells 3 in-app purchases, starting at $2.99 per month and Soln sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Thyroid Tracker ships an update every 4 days, Soln every 3 weeks. The most recent releases landed on September 5, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Thyroid Tracker | Soln |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 4 days** | Every 3 weeks |
| Size | 38 MB | 3 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Chengdu Xingguan Technology Co., Ltd.](https://appshunter.io/developer/998279524) | [Nan Yu](https://appshunter.io/developer/1559044036) |

## What reviewers say

### Thyroid Tracker

[App page](https://appshunter.io/ios/app/thyroid-tracker-hormone-log/id6753612177)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Monthly | $2.99 | per month |
| Premium Yearly | $5.99 | per year |
| Lifetime | $15.00 | one-time |


### Soln

[App page](https://appshunter.io/ios/app/soln/id6772215173)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Soln | $5.99 | one-time |


## Frequently asked questions

### Is Thyroid Tracker free?

Thyroid Tracker is free to download, with in-app purchases available.

### Is Soln free?

Soln is free to download, with in-app purchases available.

### Do Thyroid Tracker or Soln have ads?

Neither Thyroid Tracker nor Soln shows ads.

### Which is updated more often, Thyroid Tracker or Soln?

Thyroid Tracker ships an update every 4 days, and Soln every 3 weeks. Most recently, Thyroid Tracker was updated on September 5, 2026 and Soln on September 9, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*