# NEPViewer vs TSUN Smart

The clearest difference is rating: TSUN Smart at 5.0 against NEPViewer's 2.7. NEPViewer's advantage is update cadence (every 3 weeks vs every 6 weeks) and ratings volume (3 vs 1). On price, review sentiment, 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.

TSUN Smart holds the better App Store score, 5.0 against 2.7. Both are backed by a comparable volume of ratings — 3 and 1 respectively. Written reviews point the same way: 14% of NEPViewer's written reviews are positive against 18% of TSUN Smart's.

NEPViewer ships an update every 3 weeks, TSUN Smart every 6 weeks. The most recent releases landed on September 22, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | NEPViewer | TSUN Smart |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.7 (3 ratings)](https://appshunter.io/ios/app/nepviewer/id1480269247/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/tsun-smart/id6468031219/reviews)** |
| Number of ratings | **3** | 1 |
| Positive reviews | 14.3% of reviews | **18.1% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 6 weeks |
| Monetization | Free | Free |
| Size | 62 MB | 69 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Northern Electric & Power Inc](https://appshunter.io/developer/1202736933) | [TSUNESS Co., Ltd](https://appshunter.io/developer/1718029393) |

## What reviewers say

### NEPViewer

[App page](https://appshunter.io/ios/app/nepviewer/id1480269247)

Monitor your BDM micro inverter system in real-time. Track system output and energy harvest, or view installed systems and their performance. Requires registration on the NEPViewer website.

**Highlights:** Real-time system monitoring, Track energy harvest, View installed systems, Check system performance, Multi-language support

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

**In-app purchases:** none

**What reviewers like**

- 👍 Intuitive and easy to use (some users)
- ✨ Modern look and feel (some users)
- ✅ App does what it's supposed to (sometimes)

**What reviewers complain about**

- 🐛 Frequent crashes and closing
- ❌ Login and password reset issues
- 📉 Inaccurate or delayed data
- 🚫 Loss of important features (panel view, daily graphs)
- 🖥️ Poor iPad/landscape support

**Reported bugs**

- App closes immediately on launch/login
- Blank error box when resetting password
- App offline frequently
- Inaccurate wattage readings
- Cannot connect to all inverters

**Requested features**

- Restore panel performance view
- Restore daily/hourly graphs and curves
- Improve iPad/landscape mode support
- Better customer support
- Option to stay logged in


### TSUN Smart

[App page](https://appshunter.io/ios/app/tsun-smart/id6468031219)

Monitor your solar power plants and devices from your mobile. Track real-time and historical generation data, calculate yield, and visualize individual panel performance with a custom layout.

**Highlights:** Manage multiple solar plants, Add and configure devices, View real-time generation data, Review historical generation data, Calculate solar yield, Build solar panel layouts, Monitor individual panel performance

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

**In-app purchases:** none

**What reviewers like**

- 👍 Easy setup and installation process
- 📊 Clear and intuitive user interface
- 🔌 Simple WiFi connection to inverters
- ⚡ Real-time energy production monitoring
- 🎯 Straightforward configuration with serial numbers

**What reviewers complain about**

- 🐛 Frequent server outages and disconnections
- 🐛 Missing data and incomplete daily records
- 🌐 Poor German translation with numerous errors
- ⏱️ Slow app performance and sluggish updates
- 📉 Data synchronization delays (15-30 minutes)

**Reported bugs**

- Server connection failures preventing data display
- Missing daily energy data in monthly summaries
- Incorrect total energy calculations
- Data frozen or not updating in real-time
- App crashes or fails to load

**Requested features**

- Display daily peak power values consistently
- Real-time data updates on demand (pull-to-refresh)
- Export data in CSV format
- Show maximum inverter capacity information
- Email and push notifications for alerts


## Frequently asked questions

### Is NEPViewer free?

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

### Is TSUN Smart free?

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

### Which has better reviews, NEPViewer or TSUN Smart?

TSUN Smart is rated higher. NEPViewer averages 2.7 out of 5 from 3 ratings, while TSUN Smart averages 5.0 from 1 ratings.

### Do NEPViewer or TSUN Smart have ads?

Neither NEPViewer nor TSUN Smart shows ads.

### Which is updated more often, NEPViewer or TSUN Smart?

NEPViewer ships an update every 3 weeks, and TSUN Smart every 6 weeks. Most recently, NEPViewer was updated on September 22, 2026 and TSUN Smart on September 20, 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.*