This free Root and SafetyNet Checker will let you know if your device is Rooted and checks if it passes SafetyNet.

This app provides information for Root access checking it tell you if your device is Rooted checks if any SuperUser app is installed and also show you BusyBox installation on the device.

Another feature is SafetyNet checking. In order to use Android Pay your device must pass SafetyNet checking.
This app tells you if your device passes SafetyNet checking.

Note: This app does not Root your device. It just checks if your device is Rooted and will not modify any files in your system.