# PKU vs flexigym

The clearest difference is in-app purchases: flexigym at none against PKU's 1. PKU's advantage is update cadence (every 2 months vs every 10 months) and iOS requirement (8.0 vs 15.0). On price, ads and device support there is nothing between them.

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

PKU ships an update every 2 months, flexigym every 10 months. The most recent releases landed on August 9, 2026 and September 7, 2026 respectively.

## The numbers

| Metric | PKU | flexigym |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (2 ratings)](https://appshunter.io/ios/app/pku/id1046121773/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 10 months |
| Monetization | Free | — |
| Size | 22 MB | 173 MB |
| Requires iOS | **8.0** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPod, Apple Watch** |
| Age rating | 12+ | 12+ |
| Developer | [Maik Barz](https://appshunter.io/developer/891428102) | [Flexigym Anstalt](https://appshunter.io/developer/1588735252) |

## What reviewers say

### PKU

[App page](https://appshunter.io/ios/app/pku/id1046121773)

This app helps individuals manage their Phenylalanine (PHE) intake by tracking food consumption. It allows users to add custom foods, create recipes, and set supplement reminders. A daily overview shows remaining PHE allowance, and a blood value list provides a quick health summary.

**Highlights:** Track Phenylalanine (PHE) intake, Add custom foods and recipes, Daily PHE allowance overview, Supplement reminder alerts, Blood value list, Recipe management with average PHE per 100g

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock premium features | $2.99 | one-time |


### flexigym

[App page](https://appshunter.io/ios/app/flexigym/id1588735250)

**Features:** macOS Compatibility, Apple Wallet

**In-app purchases:** none


## Frequently asked questions

### Is PKU free?

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

### Is flexigym free?

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

### Do PKU or flexigym have ads?

Neither PKU nor flexigym shows ads.

### Which is updated more often, PKU or flexigym?

PKU ships an update every 2 months, and flexigym every 10 months. Most recently, PKU was updated on August 9, 2026 and flexigym on September 7, 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.*