# SmartESS vs KOSTAL Solar App

The clearest difference is rating: SmartESS at 2.7 against KOSTAL Solar App's 2.0. SmartESS also leads on ratings volume (127 vs 6). KOSTAL Solar App's advantage is review sentiment (56% vs 20%). On price, update cadence, ads and in-app purchases there is nothing between them.

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

SmartESS holds the better App Store score, 2.7 against 2.0. That said, the two scores are not equally well evidenced: SmartESS has 127 ratings behind it against 6, so its average is the more settled of the two. Written reviews complicate that: 20% of SmartESS's written reviews are positive against 56% of KOSTAL Solar App's, so the app with the better star average is not the one people write more warmly about.

SmartESS ships an update monthly, KOSTAL Solar App every 3 weeks. The most recent releases landed on October 23, 2026 and October 26, 2026 respectively.

## The numbers

| Metric | SmartESS | KOSTAL Solar App |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.7 (127 ratings)](https://appshunter.io/ios/app/smartess/id1334656760/reviews)** | [2.0 (6 ratings)](https://appshunter.io/ios/app/kostal-solar-app/id1451610122/reviews) |
| Number of ratings | **127** | 6 |
| Positive reviews | 19.7% of reviews | **56.4% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Monthly | **Every 3 weeks** |
| Monetization | Free | Free |
| Size | 198 MB | 68 MB |
| Requires iOS | **13.0** | 14.5 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [祥梯 孟](https://appshunter.io/developer/1070155084) | [KOSTAL Solar Electric GmbH](https://appshunter.io/developer/961587700) |

## What reviewers say

### SmartESS

[App page](https://appshunter.io/ios/app/smartess/id1334656760)

Monitor your energy storage machine's status in real-time with this mobile application. It offers easy-to-understand data visualization, historical data access from anywhere, and displays information in multiple dimensions. The app is designed for efficient data transfer with minimal internet traffic usage.

**Highlights:** Real-time energy storage machine monitoring, Intelligent data visualization, Simple and easy-to-understand charts, Access historical data anytime, anywhere, Multi-dimensional data display, Low internet traffic usage

**Features:** macOS Compatibility

**In-app purchases:** none


### KOSTAL Solar App

[App page](https://appshunter.io/ios/app/kostal-solar-app/id1451610122)

Monitor your photovoltaic system remotely with this free app. View generation and consumption data, access historical information, and utilize a virtual battery feature for forecasting. Requires access to the KOSTAL solar portal and an inverter.

**Highlights:** Remote photovoltaic system monitoring, View generation and consumption data, Access historical system data, 3-day generation and consumption forecast, Virtual battery simulation, Graphical data display

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

**In-app purchases:** none


## Frequently asked questions

### Is SmartESS free?

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

### Is KOSTAL Solar App free?

KOSTAL Solar App is free to download, with no in-app purchases.

### Which has better reviews, SmartESS or KOSTAL Solar App?

SmartESS is rated higher. SmartESS averages 2.7 out of 5 from 127 ratings, while KOSTAL Solar App averages 2.0 from 6 ratings.

### Do SmartESS or KOSTAL Solar App have ads?

Neither SmartESS nor KOSTAL Solar App shows ads.

### Which is updated more often, SmartESS or KOSTAL Solar App?

SmartESS ships an update monthly, and KOSTAL Solar App every 3 weeks. Most recently, SmartESS was updated on October 23, 2026 and KOSTAL Solar App on October 26, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*