# COF Training Services, Inc. vs Advanced Verbal Lab

The clearest difference is in-app purchases: COF Training Services, Inc. at none against Advanced Verbal Lab's 10. Advanced Verbal Lab's advantage is update cadence (fortnightly vs every 4 months) and device support (3 vs 1). On price, ads and iOS requirement there is nothing between them.

Both are free to download. Advanced Verbal Lab sells 10 one-off in-app purchases. COF Training Services, Inc. asks for nothing beyond the download.

COF Training Services, Inc. ships an update every 4 months, Advanced Verbal Lab fortnightly. The most recent releases landed on October 13, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | COF Training Services, Inc. | Advanced Verbal Lab |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Fortnightly** |
| Size | 143 MB | 2 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [COF Training Services, Inc.](https://appshunter.io/developer/1636975840) | [Ryoko Goto](https://appshunter.io/developer/6787639092) |

## What reviewers say

### COF Training Services, Inc.

[App page](https://appshunter.io/ios/app/cof-training-services-inc/id1636975838)

**Features:** Vision Pro support

**In-app purchases:** none


### Advanced Verbal Lab

[App page](https://appshunter.io/ios/app/advanced-verbal-lab/id6791155116)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Formula Flash II: ASSEMBLE | $2.99 | one-time |
| Formula Flash I: PARSE | $2.99 | one-time |
| Formula Flash III: RESOLVE | $2.99 | one-time |
| Context Volume III | $4.99 | one-time |
| Context Volume I | $4.99 | one-time |
| Context Volume II | $4.99 | one-time |
| Context Volume IV | $4.99 | one-time |
| The whole Formula Flash shelf | $6.99 | one-time |
| The whole Context track | $16.99 | one-time |
| The Complete Library | $21.99 | one-time |


## Frequently asked questions

### Is COF Training Services, Inc. free?

COF Training Services, Inc. is free to download, with no in-app purchases.

### Is Advanced Verbal Lab free?

Advanced Verbal Lab is free to download, with in-app purchases available.

### Do COF Training Services, Inc. or Advanced Verbal Lab have ads?

Neither COF Training Services, Inc. nor Advanced Verbal Lab shows ads.

### Which is updated more often, COF Training Services, Inc. or Advanced Verbal Lab?

COF Training Services, Inc. ships an update every 4 months, and Advanced Verbal Lab fortnightly. Most recently, COF Training Services, Inc. was updated on October 13, 2026 and Advanced Verbal Lab on October 28, 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.*