# E vs Flutter

The clearest difference is in-app purchases: E at none against Flutter's 3. E also leads on iOS requirement (10.0 vs 17.6). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Flutter sells 3 in-app purchases, starting at $14.99 per month. E asks for nothing beyond the download.

E ships an update every 5 weeks, Flutter every 3 weeks. Both last shipped on October 9, 2026.

## The numbers

| Metric | E | Flutter |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/flutter-heartbeat-sync-app/id6758436973/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Every 3 weeks** |
| Monetization | — | Subscription |
| Size | 61 MB | 21 MB |
| Requires iOS | **10.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, Apple Watch |
| Age rating | 17+ | 4+ |
| Developer | [Henan Huaxia Esti Biotech Co.,Ltd.](https://appshunter.io/developer/1231976572) | [CYBERIAN TECHNOLOGIES LLC](https://appshunter.io/developer/1872937842) |

## What reviewers say

### E

[App page](https://appshunter.io/ios/app/e-cardiac/id1129710846)

**In-app purchases:** none


### Flutter

[App page](https://appshunter.io/ios/app/flutter-heartbeat-sync-app/id6758436973)

Experience your heartbeat as a live haptic sensation on your wrist. Connect with loved ones by sharing real-time heartbeats, fostering a sense of presence and intimacy across any distance. Choose from various haptic styles for a personalized and calming experience.

**Highlights:** Live haptic heartbeat feedback on Apple Watch, Solo Sync for personal awareness, Partner Sync for sharing with others, Real-time BPM display, Multiple haptic pulse styles, Invite-based partner pairing

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Partner Sync (Monthly) | $14.99 | per month |
| Partner Sync Quarterly | $39.99 | per 3 months |
| Partner Sync Annual | $119.99 | per year |


## Frequently asked questions

### Is E free?

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

### Is Flutter free?

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

### Do E or Flutter have ads?

Neither E nor Flutter shows ads.

### Which is updated more often, E or Flutter?

E ships an update every 5 weeks, and Flutter every 3 weeks. Most recently, E was updated on October 9, 2026 and Flutter on October 9, 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.*