# 504 vs StudyForge AI

The clearest difference is price: 504 at Free against StudyForge AI's $0.99. StudyForge AI's advantage is in-app purchases (none vs 13) and ads (none vs shown). On device support and iOS requirement there is nothing between them.

504 is free to download; StudyForge AI costs $0.99 up front. 504 sells 12 in-app purchases, starting at $4.99 per 7 days. StudyForge AI asks for nothing beyond the download.

## The numbers

| Metric | 504 | StudyForge AI |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[4.8 (4.6K ratings)](https://appshunter.io/ios/app/504-vocabulary-builder/id1452101398/reviews)** | — |
| Number of ratings | **4.6K** | — |
| Positive reviews | 72.6% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Fortnightly | — |
| Monetization | Free with in-app purchases | — |
| Size | 65 MB | 1 MB |
| Requires iOS | **18.0** | 18.5 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 17+ |
| Developer | [Nefarius Apps](https://appshunter.io/developer/1792473508) | [Saul Gorman](https://appshunter.io/developer/1862650835) |

## What reviewers say

### 504

[App page](https://appshunter.io/ios/app/504-vocabulary-builder/id1452101398)

Master essential vocabulary with this language learning app. It offers clear definitions, example sentences, and native pronunciation for high-utility words. Engage with interactive games like flashcards and quizzes to reinforce learning and track your progress effectively.

**Highlights:** Essential vocabulary selection, Clear definitions and example sentences, Native pronunciation audio, Interactive learning games (flashcards, quizzes), Progress tracking tools, Multi-language support

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

**In-app purchases (12)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $4.99 | per 7 days |
| Weekly Pro Membership | $8.99 | per 7 days |
| Weekly Premium Membership | $9.99 | per 7 days |
| Premium | $9.99 | per month |
| Premium | $9.99 | per month |
| Premium | $9.99 | per 7 days |
| Monthly Pro Membership | $17.99 | per month |
| Monthly Premium Membership | $19.99 | per month |
| Premium | $34.99 | per year |
| Yearly Premium Membership | $59.99 | per year |
| Yearly Pro Membership | $59.99 | per year |
| Lifetime Access | $79.99 | one-time |

**What reviewers like**

- 🚀 Easy to learn
- 👍 Useful vocabulary practice
- 🚀 Convenient for learning on the go

**What reviewers complain about**

- 🐛 Bugs and glitches in latest version
- 🔒 Concerns about data tracking
- 🔊 Issues with pronunciation and audio

**Reported bugs**

- Pronunciation not working in latest version
- Lessons for second half of book blocked behind paywall
- Compatibility issues with older devices

**Requested features**

- Add part of speech for each word
- Include a note box for personal examples
- Add dark mode option


### StudyForge AI

[App page](https://appshunter.io/ios/app/studyforge-ai/id6756917092)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is 504 free?

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

### Is StudyForge AI free?

StudyForge AI costs $0.99, with no in-app purchases.

### Do 504 or StudyForge AI have ads?

504 shows ads; StudyForge AI does not.

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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.*