# Twin vs DevHabit

The clearest difference is price: DevHabit at Free against Twin's $0.99. Twin's advantage is in-app purchases (none vs 3) and update cadence (every 2 weeks vs every 4 months). On ads and device support there is nothing between them.

DevHabit is free to download; Twin costs $0.99 up front. DevHabit sells 3 in-app purchases, starting at $2.99 per month. Twin asks for nothing beyond the download.

Twin ships an update every 2 weeks, DevHabit every 4 months. The most recent releases landed on September 26, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | Twin | DevHabit |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | **[5.0 (8 ratings)](https://appshunter.io/ios/app/twin-calc/id1619292082/reviews)** | — |
| Number of ratings | **8** | — |
| Positive reviews | 76.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 4 months |
| Monetization | Paid | — |
| Size | 1 MB | 3 MB |
| Requires iOS | **13.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Hiroyuki Ueda](https://appshunter.io/developer/473279916) | [珍珍 张](https://appshunter.io/developer/1607946529) |

## What reviewers say

### Twin

[App page](https://appshunter.io/ios/app/twin-calc/id1619292082)

This app combines two calculators into one, allowing for side-by-side or stacked calculations. Easily copy and paste results between calculators or to other apps. It displays formulas for clarity and handles basic arithmetic operations.

**Highlights:** Two calculators in one, Side-by-side and stacked display, One-touch copy/paste between calculators, Copy results to iPhone memory, Formula display, Basic arithmetic operations

**Features:** Vision Pro support

**In-app purchases:** none


### DevHabit

[App page](https://appshunter.io/ios/app/devhabit-habit-tracker/id6752989649)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $2.99 | per month |
| Pro Yearly (Best Value) | $19.99 | per year |
| Pro Lifetime | $39.99 | one-time |


## Frequently asked questions

### Is Twin free?

Twin costs $0.99, with no in-app purchases.

### Is DevHabit free?

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

### Do Twin or DevHabit have ads?

Neither Twin nor DevHabit shows ads.

### Which is updated more often, Twin or DevHabit?

Twin ships an update every 2 weeks, and DevHabit every 4 months. Most recently, Twin was updated on September 26, 2026 and DevHabit on September 10, 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.*