# techSampler vs Rock Ace

The clearest difference is rating: Rock Ace at 5.0 against techSampler's 3.0. Rock Ace also leads on update cadence (every 4 weeks vs every 4 months). techSampler's advantage is device support (3 vs 1) and iOS requirement (7.0 vs 17.0). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. techSampler sells 1 one-off in-app purchase and Rock Ace sells 2 in-app purchases, starting at $2.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Rock Ace holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 2 and 1 respectively.

techSampler ships an update every 4 months, Rock Ace every 4 weeks. The most recent releases landed on September 4, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | techSampler | Rock Ace |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (2 ratings)](https://appshunter.io/ios/app/techsampler/id626214040/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rock-ace-ai-rock-identifier/id6759450569/reviews)** |
| Number of ratings | **2** | 1 |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 4 weeks** |
| Monetization | Free with in-app purchases | Freemium |
| Size | 38 MB | 62 MB |
| Requires iOS | **7.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Byte Works, Inc.](https://appshunter.io/developer/286319447) | [ProductiveTap](https://appshunter.io/developer/430553438) |

## What reviewers say

### techSampler

[App page](https://appshunter.io/ios/app/techsampler/id626214040)

Explore dozens of free, standalone apps with complete source code for electronics, science, math, and graphics. This companion app to a popular book provides executable projects and programming tools for iPhone and iPad.

**Highlights:** Free standalone apps with source code, Electronics and sensor projects, Data collection and analysis, Interactive graphics and programming, Companion to O'Reilly book, Built-in help and debugger, STEM education tools

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Add Editing | $14.99 | one-time |


### Rock Ace

[App page](https://appshunter.io/ios/app/rock-ace-ai-rock-identifier/id6759450569)

Instantly identify rocks, minerals, and gemstones using AI. Get detailed geological information, build a personal collection with notes and images, and engage in AI-powered discussions about geology. Export your findings as a PDF.

**Highlights:** AI rock identification, Detailed geological information, AI geology discussions, Rock collection management, Personal notes for finds, PDF export of collection

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Weekly | $2.99 | per 7 days |
| Premium Yearly | $29.99 | per year |


## Frequently asked questions

### Is techSampler free?

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

### Is Rock Ace free?

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

### Which has better reviews, techSampler or Rock Ace?

Rock Ace is rated higher. techSampler averages 3.0 out of 5 from 2 ratings, while Rock Ace averages 5.0 from 1 ratings.

### Do techSampler or Rock Ace have ads?

Neither techSampler nor Rock Ace shows ads.

### Which is updated more often, techSampler or Rock Ace?

techSampler ships an update every 4 months, and Rock Ace every 4 weeks. Most recently, techSampler was updated on September 4, 2026 and Rock Ace on September 25, 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.*