# Ultradian vs Flow

The clearest difference is in-app purchases: Ultradian at none against Flow's 3. Flow's advantage is update cadence (every 5 weeks vs every 5 months) and device support (3 vs 1). On price, ads and iOS requirement there is nothing between them.

Both are free to download. Flow sells 3 in-app purchases, starting at $1.99 per month. Ultradian asks for nothing beyond the download.

Ultradian ships an update every 5 months, Flow every 5 weeks. The most recent releases landed on September 29, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | Ultradian | Flow |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.3 (4 ratings)](https://appshunter.io/ios/app/ultradian/id1482130799/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 5 weeks** |
| Monetization | Free | — |
| Size | 7 MB | 11 MB |
| Requires iOS | 17.5 | **17.2** |
| Devices | iPhone | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Katherine Gratale](https://appshunter.io/developer/1482130798) | [Neerav Kothari](https://appshunter.io/developer/1081411587) |

## What reviewers say

### Ultradian

[App page](https://appshunter.io/ios/app/ultradian/id1482130799)

Leverage your natural energy cycles for optimal task management and rest. This app analyzes biometric data to predict your ultradian rhythms, helping you schedule demanding activities during peak energy and breaks when needed.

**Highlights:** Analyze biometric data, Predict ultradian rhythms, Schedule peak task times, Schedule rest breaks, Connects to Apple Health

**Features:** macOS Compatibility

**In-app purchases:** none


### Flow

[App page](https://appshunter.io/ios/app/flow-focus-timer/id6771008124)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Pro | $1.99 | per month |
| Yearly Pro | $14.99 | per year |
| Weekly Pass | $0.99 | one-time |


## Frequently asked questions

### Is Ultradian free?

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

### Is Flow free?

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

### Do Ultradian or Flow have ads?

Neither Ultradian nor Flow shows ads.

### Which is updated more often, Ultradian or Flow?

Ultradian ships an update every 5 months, and Flow every 5 weeks. Most recently, Ultradian was updated on September 29, 2026 and Flow on October 3, 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.*