# TET LITHIUM vs Sentry BLE

The clearest difference is update cadence: Sentry BLE at every 6 weeks against TET LITHIUM's every 32 months. TET LITHIUM's advantage is iOS requirement (9.0 vs 13.1). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

TET LITHIUM ships an update every 32 months, Sentry BLE every 6 weeks. The most recent releases landed on October 27, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | TET LITHIUM | Sentry BLE |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 32 months | **Every 6 weeks** |
| Size | 7 MB | 66 MB |
| Requires iOS | **9.0** | 13.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [宇文 钟](https://appshunter.io/developer/1541529609) | [Vision Metering](https://appshunter.io/developer/1567248925) |

## What reviewers say

### TET LITHIUM

[App page](https://appshunter.io/ios/app/tet-lithium/id1542310415)

**Features:** macOS Compatibility

**In-app purchases:** none


### Sentry BLE

[App page](https://appshunter.io/ios/app/sentry-ble/id6752409845)

**In-app purchases:** none


## Frequently asked questions

### Is TET LITHIUM free?

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

### Is Sentry BLE free?

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

### Do TET LITHIUM or Sentry BLE have ads?

Neither TET LITHIUM nor Sentry BLE shows ads.

### Which is updated more often, TET LITHIUM or Sentry BLE?

TET LITHIUM ships an update every 32 months, and Sentry BLE every 6 weeks. Most recently, TET LITHIUM was updated on October 27, 2026 and Sentry BLE on October 30, 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.*