# Callibri Biofeedback vs Serene Form

The clearest difference is device support: Serene Form at 3 against Callibri Biofeedback's 1. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Callibri Biofeedback ships an update every 4 months, Serene Form every 6 months. Both last shipped on November 3, 2026.

## The numbers

| Metric | Callibri Biofeedback | Serene Form |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.0 (1 ratings)](https://appshunter.io/ios/app/callibri-biofeedback/id1517798639/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 months** | Every 6 months |
| Monetization | Free | — |
| Size | 269 MB | 119 MB |
| Requires iOS | 16.0 | **15** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 12+ | 4+ |
| Developer | [BRAINBIT INC.](https://appshunter.io/developer/1510548622) | [Advanced Yoga Therapy, Inc](https://appshunter.io/developer/1040239993) |

## What reviewers say

### Callibri Biofeedback

[App page](https://appshunter.io/ios/app/callibri-biofeedback/id1517798639)

This system uses a sensor to measure muscle tone and visualizes your muscle activity in a game-like interface. It's designed for self-regulation training to improve muscle strength and bodily functions.

**Highlights:** Muscle tone evaluation (EMG signal), Visualizes muscle activity in games, Muscle restoration for stroke/CP, Home fitness muscle strengthening, Increases physiological reserves

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

**In-app purchases:** none


### Serene Form

[App page](https://appshunter.io/ios/app/serene-form/id6461772489)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Callibri Biofeedback free?

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

### Is Serene Form free?

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

### Do Callibri Biofeedback or Serene Form have ads?

Neither Callibri Biofeedback nor Serene Form shows ads.

### Which is updated more often, Callibri Biofeedback or Serene Form?

Callibri Biofeedback ships an update every 4 months, and Serene Form every 6 months. Most recently, Callibri Biofeedback was updated on November 3, 2026 and Serene Form on November 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.*