# keyes arm vs RCT RESS

The clearest difference is update cadence: RCT RESS at monthly against keyes arm's every 19 months. keyes arm's advantage is iOS requirement (12.0 vs 15.6). 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.

keyes arm ships an update every 19 months, RCT RESS monthly. Both last shipped on November 3, 2026.

## The numbers

| Metric | keyes arm | RCT RESS |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/rct-ress/id1577284760/reviews)** |
| Number of ratings | — | **2** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 19 months | **Monthly** |
| Monetization | — | Free |
| Size | 11 MB | 39 MB |
| Requires iOS | **12.0** | 15.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 12+ |
| Developer | [克俭 左](https://appshunter.io/developer/1449795321) | [Jiangsu RCT Power Energy Technology Co., Ltd](https://appshunter.io/developer/1577284762) |

## What reviewers say

### keyes arm

[App page](https://appshunter.io/ios/app/keyes-arm/id1487006837)

**Features:** macOS Compatibility

**In-app purchases:** none


### RCT RESS

[App page](https://appshunter.io/ios/app/rct-ress/id1577284760)

Monitor and manage inverters and energy storage systems. Developed by an energy storage company, this app offers convenient control over household, industrial, and grid energy solutions.

**Highlights:** Monitor inverters, Manage energy storage systems, Household energy solutions, Industrial energy solutions, Grid energy solutions, System monitoring

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

**In-app purchases:** none


## Frequently asked questions

### Is keyes arm free?

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

### Is RCT RESS free?

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

### Do keyes arm or RCT RESS have ads?

Neither keyes arm nor RCT RESS shows ads.

### Which is updated more often, keyes arm or RCT RESS?

keyes arm ships an update every 19 months, and RCT RESS monthly. Most recently, keyes arm was updated on November 3, 2026 and RCT RESS on November 3, 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.*