# TrueLevel Bubble Level vs US Units Guide

The clearest difference is in-app purchases: TrueLevel Bubble Level at none against US Units Guide's 3. US Units Guide's advantage is update cadence (monthly vs every 2 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. US Units Guide sells 3 one-off in-app purchases. TrueLevel Bubble Level asks for nothing beyond the download.

TrueLevel Bubble Level ships an update every 2 months, US Units Guide monthly. The most recent releases landed on October 11, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | TrueLevel Bubble Level | US Units Guide |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Monthly** |
| Size | 12 MB | 3 MB |
| Requires iOS | 18.0 | **17.0** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Ilia Filiaev](https://appshunter.io/developer/1742628366) | [BOTONG BAO](https://appshunter.io/developer/1896543904) |

## What reviewers say

### TrueLevel Bubble Level

[App page](https://appshunter.io/ios/app/truelevel-bubble-level/id6776346163)

**Features:** macOS Compatibility

**In-app purchases:** none


### US Units Guide

[App page](https://appshunter.io/ios/app/us-units-guide-unit-converter/id6784946304)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Found it useful | $0.99 | one-time |
| Support maintenance | $2.99 | one-time |
| Keep it going | $4.99 | one-time |


## Frequently asked questions

### Is TrueLevel Bubble Level free?

TrueLevel Bubble Level is free to download, with no in-app purchases.

### Is US Units Guide free?

US Units Guide is free to download, with in-app purchases available.

### Do TrueLevel Bubble Level or US Units Guide have ads?

Neither TrueLevel Bubble Level nor US Units Guide shows ads.

### Which is updated more often, TrueLevel Bubble Level or US Units Guide?

TrueLevel Bubble Level ships an update every 2 months, and US Units Guide monthly. Most recently, TrueLevel Bubble Level was updated on October 11, 2026 and US Units Guide on October 12, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*