# Sun Focus vs RPEMS

The clearest difference is price: RPEMS at Free against Sun Focus's $1.99. RPEMS also leads on iOS requirement (12.0 vs 17.0). Sun Focus's advantage is update cadence (every 4 weeks vs every 10 months). On ads, in-app purchases and device support there is nothing between them.

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

Sun Focus ships an update every 4 weeks, RPEMS every 10 months. The most recent releases landed on September 21, 2026 and May 13, 2026 respectively.

## The numbers

| Metric | Sun Focus | RPEMS |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 weeks** | Every 10 months |
| Monetization | Paid | — |
| Size | 3 MB | 13 MB |
| Requires iOS | 17.0 | **12.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Alventir Ltd](https://appshunter.io/developer/1527058758) | [Jiangsu RCT Power Energy Technology Co., Ltd](https://appshunter.io/developer/1577284762) |

## What reviewers say

### Sun Focus

[App page](https://appshunter.io/ios/app/sun-focus/id1527058756)

Visualize the sun's path, sunrise, and sunset times for any location and date. Utilize augmented reality and interactive maps to plan photography, assess sun exposure, or explore celestial phenomena.

**Highlights:** Augmented reality (AR) sun path visualization, Interactive plot and map, Sunrise and sunset time calculation, Save and bookmark locations, Customizable widgets, Location lookup by coordinates or name

**In-app purchases:** none


### RPEMS

[App page](https://appshunter.io/ios/app/rpems/id1598243104)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Sun Focus free?

Sun Focus costs $1.99, with no in-app purchases.

### Is RPEMS free?

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

### Do Sun Focus or RPEMS have ads?

Neither Sun Focus nor RPEMS shows ads.

### Which is updated more often, Sun Focus or RPEMS?

Sun Focus ships an update every 4 weeks, and RPEMS every 10 months. Most recently, Sun Focus was updated on September 21, 2026 and RPEMS on May 13, 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.*