# FEEL THIS vs String Tension Calc

The clearest difference is ads: String Tension Calc at none against FEEL THIS's shown. FEEL THIS's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 17.0). On price, update cadence and in-app purchases there is nothing between them.

Both are free to download. FEEL THIS sells 1 one-off in-app purchase and String Tension Calc sells 4 in-app purchases, starting at $2.99 per 7 days. Whichever you choose, the download price is not the number that matters.

FEEL THIS ships an update fortnightly, String Tension Calc every 3 weeks. The most recent releases landed on October 18, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | FEEL THIS | String Tension Calc |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | **Fortnightly** | Every 3 weeks |
| Size | 22 MB | 44 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [YOONGUN OH](https://appshunter.io/developer/1896754383) | [Vasilii Polovnikov](https://appshunter.io/developer/1716165883) |

## What reviewers say

### FEEL THIS

[App page](https://appshunter.io/ios/app/feel-this/id6770570242)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Pro Pass | $1.99 | one-time |


### String Tension Calc

[App page](https://appshunter.io/ios/app/string-tension-calc/id6792709631)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $2.99 | per 7 days |
| Premium | $3.99 | per month |
| Premium | $5.99 | per year |
| Lifetime | $7.99 | one-time |


## Frequently asked questions

### Is FEEL THIS free?

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

### Is String Tension Calc free?

String Tension Calc is free to download, with in-app purchases available.

### Do FEEL THIS or String Tension Calc have ads?

FEEL THIS shows ads; String Tension Calc does not.

### Which is updated more often, FEEL THIS or String Tension Calc?

FEEL THIS ships an update fortnightly, and String Tension Calc every 3 weeks. Most recently, FEEL THIS was updated on October 18, 2026 and String Tension Calc on October 21, 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.*