# BOLLbox vs TC

The clearest difference is price: BOLLbox at Free against TC's $1.99. TC's advantage is update cadence (every 3 months vs every 7 months) and iOS requirement (13.0 vs 15.6). On ads, in-app purchases and device support there is nothing between them.

BOLLbox is free to download; TC costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

BOLLbox ships an update every 7 months, TC every 3 months. The most recent releases landed on September 8, 2026 and September 15, 2026 respectively.

## The numbers

| Metric | BOLLbox | TC |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/tc-rtd-reference/id6504454500/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 3 months** |
| Monetization | — | Paid |
| Size | 29 MB | 12 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [BOLL & KIRCH Filterbau GmbH](https://appshunter.io/developer/1673939850) | [立娜 王](https://appshunter.io/developer/1761096632) |

## What reviewers say

### BOLLbox

[App page](https://appshunter.io/ios/app/bollbox/id6445814925)

**Features:** macOS Compatibility

**In-app purchases:** none


### TC

[App page](https://appshunter.io/ios/app/tc-rtd-reference/id6504454500)

This utility app provides quick and accurate conversions between resistance, potential, and temperature for various thermocouples and RTDs. It supports offline use, temperature recording with export, and offers an intuitive interface for field technicians and engineers.

**Highlights:** Thermocouple and RTD conversion, Supports multiple sensor types, Offline functionality, Temperature recording and charting, Export data to Excel, Intuitive user interface

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

**In-app purchases:** none


## Frequently asked questions

### Is BOLLbox free?

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

### Is TC free?

TC costs $1.99, with no in-app purchases.

### Do BOLLbox or TC have ads?

Neither BOLLbox nor TC shows ads.

### Which is updated more often, BOLLbox or TC?

BOLLbox ships an update every 7 months, and TC every 3 months. Most recently, BOLLbox was updated on September 8, 2026 and TC on September 15, 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.*