# Flutter vs SPINE

Flutter and SPINE are too close to call on the numbers: across 5 compared parameters — price, ads, in-app purchases and device support among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Both are free to download. Flutter sells 3 in-app purchases, starting at $14.99 per month and SPINE sells 3 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

## The numbers

| Metric | Flutter | SPINE |
| --- | --- | --- |
| 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 | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | — |
| Monetization | Subscription | — |
| Size | 21 MB | 8 MB |
| Requires iOS | 17.6 | **17.0** |
| Devices | **iPhone, Apple Watch** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [CYBERIAN TECHNOLOGIES LLC](https://appshunter.io/developer/1872937842) | [No Worries! Lifestyle, LLC](https://appshunter.io/developer/1517663033) |

## What reviewers say

### 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 |


### SPINE

[App page](https://appshunter.io/ios/app/spine-tech-neck-posture-fix/id6765985749)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $9.99 | per month |
| Pro Yearly | $39.99 | per year |
| Pro Lifetime | $99.99 | one-time |


## Frequently asked questions

### Is Flutter free?

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

### Is SPINE free?

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

### Do Flutter or SPINE have ads?

Neither Flutter nor SPINE shows ads.

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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.*