# j901 — user reviews

> 6 indexed App Store user reviews of j901 by Ian Clark, rated 5.00/5 from 8 ratings.

- Source: https://appshunter.io/ios/app/j901/id1483497239/reviews
- App overview in markdown: https://appshunter.io/ios/app/j901/id1483497239.md
- Rating breakdown: 5★ 8 · 4★ 0 · 3★ 0 · 2★ 0 · 1★ 0

## Most critical reviews (6 lowest-rated)

### 5/5 — Latest update made it stop opening on my iphone XR

*2023-04-21*

Other than that it's fantastic

### 5/5 — Excellent

*2022-12-11, version 1.1*

Outstanding port of J to IOS. Very handy.

### 5/5 — J Everywhere

*2022-11-14*

To paraphrase a well known photographers’ saying, “the best computer language is the one you have with you”. Such a useful tool to have available whenever you need it. Two issues to feedback: 1. the plot package is reported as corrupted. 2. The controls at the top of the screen are partially obscured by the display island/notch on newer iPhones, so are hard to use.

As an update, deleting the previous version and then reinstalling from scratch fixed the plot package issue.

### 5/5 — Phenomenal!

*2022-10-31, version 1.0*

So thankful this was put together! Only programming language I use on my phone

### 5/5 — Great upgrade

*2022-07-23*

Been using your app 3 weeks, on iPhone, a way better version than J701. Wish there was an APL app too, for iOS, as I find the symbols easier for visualisation / recall, even if I then write it in J!

### 5/5 — Excellent implementation of J.

*2021-11-18*

Very handy companion to desktop/laptop implementation.   Vastly superior to previous implementation.   Enjoy J on your phone.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*