# TrueOffset vs CalMirror

The clearest difference is in-app purchases: TrueOffset at none against CalMirror's 2. TrueOffset also leads on ads (none vs shown). CalMirror's advantage is iOS requirement (15.1 vs 17.6). On price, update cadence and device support there is nothing between them.

Both are free to download. CalMirror sells 2 in-app purchases, starting at $2.99 per month. TrueOffset asks for nothing beyond the download.

TrueOffset ships an update fortnightly, CalMirror every 3 weeks. Both last shipped on October 28, 2026.

## The numbers

| Metric | TrueOffset | CalMirror |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (8 ratings)](https://appshunter.io/ios/app/trueoffset/id6757518499/reviews)** | — |
| Number of ratings | **8** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Fortnightly** | Every 3 weeks |
| Monetization | Free | — |
| Size | 4 MB | 40 MB |
| Requires iOS | 17.6 | **15.1** |
| Devices | iPhone, iPad, Apple TV | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Richard Bollar](https://appshunter.io/developer/1864304955) | [bad-company Incorporated](https://appshunter.io/developer/1618167935) |

## What reviewers say

### TrueOffset

[App page](https://appshunter.io/ios/app/trueoffset/id6757518499)

This app precisely measures your device's clock accuracy against global time servers. It offers multiple clock faces, time scales, and audible time signals, including radio time codes. Analyze time source quality with detailed charts and compare IPv4/IPv6 responses.

**Highlights:** NTP server comparison, Multiple clock faces (analog, digital, NTP offset), UTC & TAI time scales, Audible time signals and radio time codes, Dual-stack IPv4/IPv6 comparison, Flexible time source selection, Quality analytics charts

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

**In-app purchases:** none


### CalMirror

[App page](https://appshunter.io/ios/app/calmirror-multi-calendar-sync/id6759219374)

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Monthly | $2.99 | per month |
| Premium Yearly | $29.99 | per year |


## Frequently asked questions

### Is TrueOffset free?

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

### Is CalMirror free?

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

### Do TrueOffset or CalMirror have ads?

CalMirror shows ads; TrueOffset does not.

### Which is updated more often, TrueOffset or CalMirror?

TrueOffset ships an update fortnightly, and CalMirror every 3 weeks. Most recently, TrueOffset was updated on October 28, 2026 and CalMirror 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.*