# API653 Storage Tank Inspector vs KeenIELTS

The clearest difference is in-app purchases: KeenIELTS at none against API653 Storage Tank Inspector's 1. KeenIELTS also leads on update cadence (every 4 days vs every 5 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. API653 Storage Tank Inspector sells 1 in-app purchase, starting at $9.00 per month. KeenIELTS asks for nothing beyond the download.

API653 Storage Tank Inspector ships an update every 5 months, KeenIELTS every 4 days. The most recent releases landed on October 28, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | API653 Storage Tank Inspector | KeenIELTS |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/keenielts/id6777555210/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 4 days** |
| Monetization | — | Free |
| Size | 3 MB | 4 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Ambitionz Apps](https://appshunter.io/developer/1764753535) | [Kevin Valani](https://appshunter.io/developer/6777555212) |

## What reviewers say

### API653 Storage Tank Inspector

[App page](https://appshunter.io/ios/app/api653-storage-tank-inspector/id6756944847)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| API 653 Storage Tank Inspector | $9.00 | per month |


### KeenIELTS

[App page](https://appshunter.io/ios/app/keenielts/id6777555210)

Prepare for your IELTS exam with comprehensive practice tests and AI-powered feedback on your writing and speaking. Track your progress with detailed score breakdowns and focus your studies effectively to achieve your target band score.

**Highlights:** Full-length practice tests (4 modules), AI feedback on Writing and Speaking, Detailed band score tracking, Module-specific performance breakdown, Distraction-free test environment, Instant scoring for Listening

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

**In-app purchases:** none


## Frequently asked questions

### Is API653 Storage Tank Inspector free?

API653 Storage Tank Inspector is free to download, with in-app purchases available.

### Is KeenIELTS free?

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

### Do API653 Storage Tank Inspector or KeenIELTS have ads?

Neither API653 Storage Tank Inspector nor KeenIELTS shows ads.

### Which is updated more often, API653 Storage Tank Inspector or KeenIELTS?

API653 Storage Tank Inspector ships an update every 5 months, and KeenIELTS every 4 days. Most recently, API653 Storage Tank Inspector was updated on October 28, 2026 and KeenIELTS on October 31, 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.*