# Shift Unit vs ProseKey AI

The clearest difference is update cadence: ProseKey AI at fortnightly against Shift Unit's every 2 months. Shift Unit's advantage is ratings volume (21 vs 1). On price, rating, 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.

On the App Store both sit at effectively the same score — 5.0 for Shift Unit against 5.0 for ProseKey AI. That said, the two scores are not equally well evidenced: Shift Unit has 21 ratings behind it against 1, so its average is the more settled of the two.

Shift Unit ships an update every 2 months, ProseKey AI fortnightly. The most recent releases landed on September 21, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | Shift Unit | ProseKey AI |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (21 ratings)](https://appshunter.io/ios/app/shift-unit/id1514037983/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/prosekey-ai/id6741180175/reviews) |
| Number of ratings | **21** | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Fortnightly** |
| Monetization | Free | Free |
| Size | 20 MB | 29 MB |
| Requires iOS | 16.0 | 16.0 |
| Devices | iPhone, Apple Watch | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Didier Burton](https://appshunter.io/developer/1514037982) | [Arya Mirsepasi](https://appshunter.io/developer/1791440463) |

## What reviewers say

### Shift Unit

[App page](https://appshunter.io/ios/app/shift-unit/id1514037983)

This utility app offers precise unit and currency conversions with over 1400 units across 34 categories. It supports light/dark modes, home widgets, and an independent Apple Watch app. Features include a custom keypad with calculator mode and educational Wikipedia integration.

**Highlights:** 1400+ conversion units, 34 categories, Light/dark mode support, Home widget, Apple Watch app, Custom keypad with calculator, Wikipedia integration

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

**In-app purchases:** none


### ProseKey AI

[App page](https://appshunter.io/ios/app/prosekey-ai/id6741180175)

Enhance your mobile writing with an AI-powered keyboard. It offers instant proofreading, effortless rewriting, quick summarization, and text-to-table conversion. Connect your own API keys for personalized AI assistance across all your apps.

**Highlights:** Instant proofreading, Effortless rewriting, Quick summarization, Text-to-table conversion, Custom AI instructions, Third-party keyboard integration

**In-app purchases:** none


## Frequently asked questions

### Is Shift Unit free?

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

### Is ProseKey AI free?

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

### Which has better reviews, Shift Unit or ProseKey AI?

Shift Unit and ProseKey AI are both rated 5.0 out of 5 on the App Store, from 21 and 1 ratings respectively.

### Do Shift Unit or ProseKey AI have ads?

Neither Shift Unit nor ProseKey AI shows ads.

### Which is updated more often, Shift Unit or ProseKey AI?

Shift Unit ships an update every 2 months, and ProseKey AI fortnightly. Most recently, Shift Unit was updated on September 21, 2026 and ProseKey AI on September 20, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*