# Concise ISL vs VDI

The clearest difference is price: VDI at Free against Concise ISL's $1.99. VDI also leads on update cadence (every 6 weeks vs every 25 months). Concise ISL's advantage is ads (none vs shown) and iOS requirement (9.0 vs 13.0). On review sentiment, in-app purchases and device support there is nothing between them.

VDI is free to download; Concise ISL costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Concise ISL ships an update every 25 months, VDI every 6 weeks. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Concise ISL | VDI |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 25 months | **Every 6 weeks** |
| Monetization | Paid | **Ad-supported** |
| Size | 25 MB | 65 MB |
| Requires iOS | **9.0** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kevin Doherty](https://appshunter.io/developer/1046591870) | [Ross Smith](https://appshunter.io/developer/1662466548) |

## What reviewers say

### Concise ISL

[App page](https://appshunter.io/ios/app/concise-isl/id1046591871)

Learn Irish Sign Language with a comprehensive video dictionary featuring around 1000 signs. Explore signs by category, search efficiently, and access offline content. Ideal for learners of all ages.

**Highlights:** 1000+ ISL signs in video format, High-quality image support for signs, Categorized sign organization, Efficient search functionality, Offline use after initial download, Child-appropriate content, Information on ISL history and grammar

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

**In-app purchases:** none


### VDI

[App page](https://appshunter.io/ios/app/vdi-irish-theory-and-test-prep/id1662466546)

Prepare for your Irish Theory and Driving Tests with this comprehensive app. It offers extensive practice questions, mock exams, and video lessons covering all essential topics. Designed by driving instructors, it aims to help learners pass faster and with less stress.

**Highlights:** 800+ official style theory questions, Mock and custom theory tests, Road signs and examiner questions, Bonnet check and control lessons, 40+ video driving lessons, Updated for latest RSA syllabus

**Features:** macOS Compatibility, Apple Wallet

**In-app purchases:** none


## Frequently asked questions

### Is Concise ISL free?

Concise ISL costs $1.99, with no in-app purchases.

### Is VDI free?

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

### Do Concise ISL or VDI have ads?

VDI shows ads; Concise ISL does not.

### Which is updated more often, Concise ISL or VDI?

Concise ISL ships an update every 25 months, and VDI every 6 weeks. Most recently, Concise ISL was updated on November 2, 2026 and VDI on November 3, 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.*