# My Solar Panel vs Keystone

The clearest difference is in-app purchases: Keystone at none against My Solar Panel's 2. Keystone also leads on ads (none vs shown) and update cadence (fortnightly vs every 2 months). My Solar Panel's advantage is device support (3 vs 1) and iOS requirement (13.2 vs 17.0). On price there is nothing between them.

Both are free to download. My Solar Panel sells 2 in-app purchases, starting at $9.99 per month. Keystone asks for nothing beyond the download.

My Solar Panel ships an update every 2 months, Keystone fortnightly. The most recent releases landed on October 11, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | My Solar Panel | Keystone |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (108 ratings)](https://appshunter.io/ios/app/my-solar-panel/id1498356619/reviews)** | — |
| Number of ratings | **108** | — |
| Positive reviews | 42.9% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 2 months | **Fortnightly** |
| Monetization | Free with in-app purchases | — |
| Size | 12 MB | 4 MB |
| Requires iOS | **13.2** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Igor Ilijovski](https://appshunter.io/developer/1492982127) | [Ionut Mocanu](https://appshunter.io/developer/1648541447) |

## What reviewers say

### My Solar Panel

[App page](https://appshunter.io/ios/app/my-solar-panel/id1498356619)

Design and analyze solar photovoltaic systems on your smartphone. Get electricity generation estimates, payback periods, and detailed financial analyses for rooftop or commercial installations. Optimize your system for maximum output and make informed investment decisions.

**Highlights:** Design solar projects on mobile, Estimate electricity generation, Calculate payback period, Generate PDF reports, 3D panel simulator, Shading analysis, Financial analysis tools

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock all features | $9.99 | per month |
| Unlock all features | $39.99 | per year |


### Keystone

[App page](https://appshunter.io/ios/app/keystone-project-tracker/id6760302143)

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

**In-app purchases:** none


## Frequently asked questions

### Is My Solar Panel free?

My Solar Panel is free to download, with in-app purchases available.

### Is Keystone free?

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

### Do My Solar Panel or Keystone have ads?

My Solar Panel shows ads; Keystone does not.

### Which is updated more often, My Solar Panel or Keystone?

My Solar Panel ships an update every 2 months, and Keystone fortnightly. Most recently, My Solar Panel was updated on October 11, 2026 and Keystone on October 7, 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.*