A free program for Android, by CPCER Studio.
You can quickly and easily determine whether your phone has been "Rooted" by using the "Root Checker - Device Info Super SU" tab. You can also choose to receive additional information about the busybox and su executables.
This software offers even the most novice Android user a quick way to determine whether root (administrator, superuser, or su) access is enabled on their device.
With a very straightforward user interface, the Root Checker - Device Info and Super SU software easily alert the user whether or whether they have root (superuser) access set up correctly.
Don't forget that this app won't root your phone.