# CalmTide vs Luid

The clearest difference is iOS requirement: CalmTide at 18.6 against Luid's 26.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. CalmTide sells 3 in-app purchases, starting at $4.99 per month and Luid sells 2 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

CalmTide ships an update every 10 days, Luid weekly. The most recent releases landed on October 15, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | CalmTide | Luid |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 10 days | **Weekly** |
| Size | 9 MB | 5 MB |
| Requires iOS | **18.6** | 26.0 |
| Devices | **iPhone, iPad, Apple Watch** | iPhone, Apple Watch |
| Age rating | 12+ | 12+ |
| Developer | [Michael Smith](https://appshunter.io/developer/1893971383) | [Ali Yigit](https://appshunter.io/developer/1896336668) |

## What reviewers say

### CalmTide

[App page](https://appshunter.io/ios/app/calmtide-cortisol-tracker/id6776101012)

**Features:** Apple Watch app

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $4.99 | per month |
| Annual | $29.99 | per year |
| Lifetime | $59.99 | one-time |


### Luid

[App page](https://appshunter.io/ios/app/luid/id6777601157)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Luid PRO Monthly | $0.99 | per month |
| Luid PRO Yearly | $1.99 | per year |


## Frequently asked questions

### Is CalmTide free?

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

### Is Luid free?

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

### Do CalmTide or Luid have ads?

Neither CalmTide nor Luid shows ads.

### Which is updated more often, CalmTide or Luid?

CalmTide ships an update every 10 days, and Luid weekly. Most recently, CalmTide was updated on October 15, 2026 and Luid on October 10, 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.*