# Thermal Pro vs Spelling Test

The clearest difference is in-app purchases: Thermal Pro at none against Spelling Test's 3. Thermal Pro also leads on iOS requirement (12.0 vs 17.6). Spelling Test's advantage is update cadence (weekly vs every 4 months). On price, ads and device support there is nothing between them.

Both are free to download. Spelling Test sells 3 in-app purchases, starting at $1.99 per month. Thermal Pro asks for nothing beyond the download.

Thermal Pro ships an update every 4 months, Spelling Test weekly. The most recent releases landed on October 24, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Thermal Pro | Spelling Test |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/thermal-pro/id6736890047/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Weekly** |
| Monetization | Free | — |
| Size | 28 MB | 4 MB |
| Requires iOS | **12.0** | 17.6 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 9+ |
| Developer | [Shenzhen Leagend Optoelectronics Co., Ltd.](https://appshunter.io/developer/6798210621) | [晓光 赵](https://appshunter.io/developer/1885174861) |

## What reviewers say

### Thermal Pro

[App page](https://appshunter.io/ios/app/thermal-pro/id6736890047)

This portable thermal imager converts object heat radiation into images and temperature data. It offers high-resolution thermal imaging, real-time temperature measurement, and various display modes. Users can record videos, set alarms, and generate detailed analysis reports.

**Highlights:** 256x192 pixel infrared resolution, Real-time high-definition thermal imaging, Temperature range -20℃ to 550℃, Thermal imaging, fusion, and picture-in-picture modes, Real-time temperature sound/light alarms, Temperature measurement analysis reports, Video recording and playback

**Features:** macOS Compatibility

**In-app purchases:** none


### Spelling Test

[App page](https://appshunter.io/ios/app/spelling-test-spell-up/id6786974788)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Spell-Up Plus Monthly | $1.99 | per month |
| Spell-Up Plus Annual | $9.99 | per year |
| Lifetime Access | $14.99 | one-time |


## Frequently asked questions

### Is Thermal Pro free?

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

### Is Spelling Test free?

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

### Do Thermal Pro or Spelling Test have ads?

Neither Thermal Pro nor Spelling Test shows ads.

### Which is updated more often, Thermal Pro or Spelling Test?

Thermal Pro ships an update every 4 months, and Spelling Test weekly. Most recently, Thermal Pro was updated on October 24, 2026 and Spelling Test 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.*