# LSTclock vs GPSTime

The clearest difference is rating: GPSTime at 5.0 against LSTclock's 3.8. GPSTime also leads on update cadence (every 2 weeks vs every 2 months). LSTclock's advantage is ratings volume (10 vs 1). On price, ads, in-app purchases and monetization model there is nothing between them.

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

GPSTime holds the better App Store score, 5.0 against 3.8. That said, the two scores are not equally well evidenced: LSTclock has 10 ratings behind it against 1, so its average is the more settled of the two.

LSTclock ships an update every 2 months, GPSTime every 2 weeks. The most recent releases landed on September 9, 2026 and June 2, 2026 respectively.

## The numbers

| Metric | LSTclock | GPSTime |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.8 (10 ratings)](https://appshunter.io/ios/app/lstclock-sidereal-time-clock/id1510148631/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/gpstime/id6751814380/reviews)** |
| Number of ratings | **10** | 1 |
| Positive reviews | 54.5% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Monetization | Free | Free |
| Size | 15 MB | 25 MB |
| Requires iOS | **17.0** | 18.5 |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, Mac |
| Age rating | 4+ | 4+ |
| Developer | [Tsuyoshi Sawada](https://appshunter.io/developer/1510148630) | [Gimin Kim](https://appshunter.io/developer/1836958729) |

## What reviewers say

### LSTclock

[App page](https://appshunter.io/ios/app/lstclock-sidereal-time-clock/id1510148631)

This utility app displays local sidereal time for registered locations on iOS, iPadOS, and watchOS. It can also calculate sidereal time and Julian Date for any date and time, and sync locations between devices.

**Highlights:** Local sidereal time display, Julian Date calculation, Supports multiple registered locations, Location sync between iPhone and Apple Watch, Date and time specific calculations

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### GPSTime

[App page](https://appshunter.io/ios/app/gpstime/id6751814380)

This tool converts between GPS Time and UTC, supporting various formats like GPS Week, Gregorian calendar, and Modified Julian Date. It accurately handles leap seconds and saves conversion history for GNSS professionals, researchers, and students.

**Highlights:** GPS Time to UTC conversion, Support for leap seconds, Multiple time format support, Conversion history saving, Configurable default scenarios, Clean interface

**In-app purchases:** none


## Frequently asked questions

### Is LSTclock free?

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

### Is GPSTime free?

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

### Which has better reviews, LSTclock or GPSTime?

GPSTime is rated higher. LSTclock averages 3.8 out of 5 from 10 ratings, while GPSTime averages 5.0 from 1 ratings.

### Do LSTclock or GPSTime have ads?

Neither LSTclock nor GPSTime shows ads.

### Which is updated more often, LSTclock or GPSTime?

LSTclock ships an update every 2 months, and GPSTime every 2 weeks. Most recently, LSTclock was updated on September 9, 2026 and GPSTime on June 2, 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.*