# Correlate vs CalmTide

The clearest difference is price: CalmTide at Free against Correlate's $12.99. Correlate's advantage is in-app purchases (none vs 3) and iOS requirement (16.0 vs 26.0). On update cadence, ads and device support there is nothing between them.

CalmTide is free to download; Correlate costs $12.99 up front. CalmTide sells 3 in-app purchases, starting at $4.99 per month. Correlate asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 3 weeks. Both last shipped on October 31, 2026.

## The numbers

| Metric | Correlate | CalmTide |
| --- | --- | --- |
| Price | $12.99 | **Free** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Size | 2 MB | 10 MB |
| Requires iOS | **16.0** | 26.0 |
| Devices | iPhone, iPad | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 12+ |
| Developer | [James Michael Beck](https://appshunter.io/developer/1877941198) | [Michael Smith](https://appshunter.io/developer/1893971383) |

## What reviewers say

### Correlate

[App page](https://appshunter.io/ios/app/correlate-life-journal/id6759300356)

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

**In-app purchases:** none


### 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 |


## Frequently asked questions

### Is Correlate free?

Correlate costs $12.99, with no in-app purchases.

### Is CalmTide free?

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

### Do Correlate or CalmTide have ads?

Neither Correlate nor CalmTide shows ads.

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

Correlate ships an update every 3 weeks, and CalmTide every 3 weeks. Most recently, Correlate was updated on October 31, 2026 and CalmTide on October 31, 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.*