MiniWatts

MiniWatts is an open-source iPhone battery and charging monitor built on Apple’s private APIs. It reads the phone’s own power-management sensors — the same ones iOS uses to run the charge — and shows what the charger is delivering, how much of it actually reaches the cell, where the rest goes as heat, and what every temperature sensor in the phone is doing while it happens.

Key features:

• Power — live charger input, power into the cell, and the conversion loss in between
• Thermal — every temperature sensor the phone exposes, while it charges
• Adapter — the charger’s rated wattage, how much of it is actually used, and the resistance of the whole charging path — handy for comparing cables on the same charger
• History — every charging session recorded
• Home Screen and Lock Screen widgets, plus a Live Activity while charging
• A floating Picture-in-Picture meter that keeps updating every second, even in other apps or with the screen locked
• A Shortcuts action that hands a live reading to your automations — e.g. switch a smart plug off when the battery gets hot

Privacy: There is no network code of any kind — nothing MiniWatts reads ever leaves your phone.

Install: Because it uses private APIs, MiniWatts can never be on the App Store; you sign and install it yourself. Download MiniWatts-unsigned.ipa from GitHub Releases and sign it with your own Apple ID using Sideloadly, AltStore, SideStore or Xcode (a free Apple ID works, but the app expires after seven days). Or add the source below to SideStore / AltStore so new versions show up as updates:

https://github.com/ResistanceTo/MiniWatts/releases/latest/download/apps.json

Requires iPhone with iOS 17 or later. Built with Xcode 26 and Swift, with no third-party dependencies, and released under the Apache 2.0 licence.