# innios vs Undercurrent

The clearest difference is in-app purchases: innios at none against Undercurrent's 1. Undercurrent's advantage is update cadence (weekly vs every 2 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Undercurrent sells 1 one-off in-app purchase. innios asks for nothing beyond the download.

innios ships an update every 2 weeks, Undercurrent weekly. Both last shipped on October 28, 2026.

## The numbers

| Metric | innios | Undercurrent |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Weekly** |
| Size | 40 MB | 73 MB |
| Requires iOS | **16.0** | 16.4 |
| Devices | iPhone, iPad, Mac | iPhone, iPad, Apple Watch |
| Age rating | 17+ | 12+ |
| Developer | [Trails Software Inc.](https://appshunter.io/developer/1874802909) | [Lloyd Rowat](https://appshunter.io/developer/1166734628) |

## What reviewers say

### innios

[App page](https://appshunter.io/ios/app/innios/id6758752046)

**In-app purchases:** none


### Undercurrent

[App page](https://appshunter.io/ios/app/undercurrent-symptom-log/id6759209174)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Undercurrent Health: Pro | $19.99 | one-time |


## Frequently asked questions

### Is innios free?

innios is free to download, with no in-app purchases.

### Is Undercurrent free?

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

### Do innios or Undercurrent have ads?

Neither innios nor Undercurrent shows ads.

### Which is updated more often, innios or Undercurrent?

innios ships an update every 2 weeks, and Undercurrent weekly. Most recently, innios was updated on October 28, 2026 and Undercurrent on October 28, 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.*