This app allows you to test the correct operation of many parts of your device (phone or tablet). You can test the following:
*Device's sensors: accelerometer, gyroscope, compass...
*Wifi: internal & external IP, gateway, DHCP server...
*GPS: satellites, latitude, longitude, speed...
*Battery: health, level of charge...
*Multitouch screen: how many fingers recognize your device?(not available in Android 1.6)
Also displays system information about hardware and software like CPU properties, RAM, storage, kernel version, screen, ...