PCB Duo
Learn electronics by building a phone. 12 units — from Ohm's law to a custom PCB.
Download for Android (APK)
~17 MB · Android 5.0+
Open in browser
Works on iPhone, Android, and desktop
Android install: after downloading, tap the file. Android
will warn about "unknown sources" — that's normal for apps installed
outside the Play Store. Allow it and the app installs.
iPhone: tap "Open in browser", then use Safari's Share
menu → "Add to Home Screen" to install it like an app.