Whether you're curious about a device you purchased or want to see how well a phone runs before you sell it, here are the best diagnostic tools for iPhone and Android.

TestM for iPhone and Android Designed for iOS and Android, the free TestM app can run diagnostics on your phone's touch screen, sound, camera, sensors, network connectivity, and other hardware.

Curious how well the battery inside your iPhone is doing? Here's how to check it.

After the blowback, Apple added a Battery Health feature to the iPhone, revealing how well -- or poorly -- your iPhone battery is performing, and letting you know when it's time to have the ...

Automatic Link is a new hardware dongle for your car that is launching today and will allow you to monitor on-board diagnostics directly on your iPhone. On top of monitoring on-board diagnostics ...