# Justinmind vs Principle Mirror

The clearest difference is rating: Principle Mirror at 4.2 against Justinmind's 3.3. Principle Mirror also leads on update cadence (every 2 months vs every 5 months). On price, review sentiment, ratings volume and ads there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Principle Mirror holds the better App Store score, 4.2 against 3.3. Both are backed by a comparable volume of ratings — 15 and 14 respectively. Written reviews complicate that: 52% of Justinmind's written reviews are positive against 45% of Principle Mirror's, so the app with the better star average is not the one people write more warmly about.

Justinmind ships an update every 5 months, Principle Mirror every 2 months. The most recent releases landed on June 9, 2026 and September 19, 2026 respectively.

## The numbers

| Metric | Justinmind | Principle Mirror |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.3 (15 ratings)](https://appshunter.io/ios/app/justinmind/id891264087/reviews) | **[4.2 (14 ratings)](https://appshunter.io/ios/app/principle-mirror/id991911319/reviews)** |
| Number of ratings | **15** | 14 |
| Positive reviews | **52.4% of reviews** | 45.2% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | Free | Free |
| Size | 8 MB | 1 MB |
| Requires iOS | 12.0 | **11.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Justinmind](https://appshunter.io/developer/891264090) | [Daniel Hooper](https://appshunter.io/developer/419502228) |

## What reviewers say

### Justinmind

[App page](https://appshunter.io/ios/app/justinmind/id891264087)

Create fully functional mobile app prototypes with advanced gestures, transitions, and effects. View and test your designs on mobile devices, even offline, for seamless demos and presentations.

**Highlights:** Create interactive prototypes, Mobile gestures and transitions, Offline prototype viewing, Cloud sharing, Mobile and tablet adaptation

**In-app purchases:** none


### Principle Mirror

[App page](https://appshunter.io/ios/app/principle-mirror/id991911319)

Design interactive user interfaces with this companion app for a popular Mac design tool. Seamlessly open Principle files or mirror your Mac's design work directly to your device.

**Highlights:** Open Principle files, Mirror Principle for Mac, Interactive UI design, Companion app functionality

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Justinmind free?

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

### Is Principle Mirror free?

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

### Which has better reviews, Justinmind or Principle Mirror?

Principle Mirror is rated higher. Justinmind averages 3.3 out of 5 from 15 ratings, while Principle Mirror averages 4.2 from 14 ratings.

### Do Justinmind or Principle Mirror have ads?

Neither Justinmind nor Principle Mirror shows ads.

### Which is updated more often, Justinmind or Principle Mirror?

Justinmind ships an update every 5 months, and Principle Mirror every 2 months. Most recently, Justinmind was updated on June 9, 2026 and Principle Mirror on September 19, 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.*