# ZT vs UPENERGY

The clearest difference is review sentiment: UPENERGY at 100% against ZT's 18%. UPENERGY also leads on rating (5.0 vs 4.6). ZT's advantage is ratings volume (285 vs 2) and device support (3 vs 1). 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.

UPENERGY holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: ZT has 285 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 18% of ZT's written reviews are positive against 100% of UPENERGY's.

ZT ships an update every 3 weeks, UPENERGY every 4 weeks. The most recent releases landed on November 1, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | ZT | UPENERGY |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.6 (285 ratings)](https://appshunter.io/ios/app/zt/id1214656147/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/upenergy/id6751304259/reviews)** |
| Number of ratings | **285** | 2 |
| Positive reviews | 18.5% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 4 weeks |
| Monetization | Free | Free |
| Size | 121 MB | 153 MB |
| Requires iOS | **12.0** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [ZTK, OOO](https://appshunter.io/developer/1577726159) | [Shishelyakin Nickolay Evgenevich, IP](https://appshunter.io/developer/1834549668) |

## What reviewers say

### ZT

[App page](https://appshunter.io/ios/app/zt/id1214656147)

Connect with incarcerated individuals through a comprehensive mobile service. Send letters, photos, make audio/video calls, and transfer funds. Offers entertainment options like puzzles and games to enrich communication.

**Highlights:** Send electronic letters and photos, Make audio and video calls, Transfer money to inmate accounts, Add puzzles and games to letters, Instant printing at correctional facilities

**Features:** Vision Pro support

**In-app purchases:** none


### UPENERGY

[App page](https://appshunter.io/ios/app/upenergy/id6751304259)

Rent a portable charger in just a few clicks. This service allows you to pick up and return power banks at convenient locations, equipped with popular charging cables. It's designed for on-the-go power needs.

**Highlights:** Rent power banks easily, Pick up and return anywhere, Includes 3 popular cable types, Stations in malls, cafes, and transport hubs, Simple registration and usage

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

**In-app purchases:** none


## Frequently asked questions

### Is ZT free?

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

### Is UPENERGY free?

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

### Which has better reviews, ZT or UPENERGY?

UPENERGY is rated higher. ZT averages 4.6 out of 5 from 285 ratings, while UPENERGY averages 5.0 from 2 ratings.

### Do ZT or UPENERGY have ads?

Neither ZT nor UPENERGY shows ads.

### Which is updated more often, ZT or UPENERGY?

ZT ships an update every 3 weeks, and UPENERGY every 4 weeks. Most recently, ZT was updated on November 1, 2026 and UPENERGY on October 17, 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.*