# The Sustainer vs Wattmax SmartCharge

The clearest difference is update cadence: Wattmax SmartCharge at every 3 months against The Sustainer's every 8 months. The Sustainer's advantage is iOS requirement (13.0 vs 16.6). 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.

The Sustainer ships an update every 8 months, Wattmax SmartCharge every 3 months. The most recent releases landed on September 16, 2026 and September 7, 2026 respectively.

## The numbers

| Metric | The Sustainer | Wattmax SmartCharge |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 8 months | **Every 3 months** |
| Size | 64 MB | 96 MB |
| Requires iOS | **13.0** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 17+ |
| Developer | [ENVO-SUSTAINER PRIVATE LIMITED](https://appshunter.io/developer/1680880040) | [Wattmax SmartCharge](https://appshunter.io/developer/1822294803) |

## What reviewers say

### The Sustainer

[App page](https://appshunter.io/ios/app/the-sustainer/id6447298071)

**Features:** macOS Compatibility, Apple Wallet

**In-app purchases:** none


### Wattmax SmartCharge

[App page](https://appshunter.io/ios/app/wattmax-smartcharge/id6747673557)

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

**In-app purchases:** none


## Frequently asked questions

### Is The Sustainer free?

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

### Is Wattmax SmartCharge free?

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

### Do The Sustainer or Wattmax SmartCharge have ads?

Neither The Sustainer nor Wattmax SmartCharge shows ads.

### Which is updated more often, The Sustainer or Wattmax SmartCharge?

The Sustainer ships an update every 8 months, and Wattmax SmartCharge every 3 months. Most recently, The Sustainer was updated on September 16, 2026 and Wattmax SmartCharge on September 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.*