Someone is using this app to trace all my messages and has no permission. How do I get rid of this? They are harassing me. Any help would be appreciated.
First of all, delete all the data of your phone by factory reset.
Secondly, download an anti-virus [avast! recommended] and scan your whole phone system.
Please put your phone into Recovery Menu by pressing the general key combination: Volume Up + Power Button. Once in Recovery, select Wipe Data/Factory Reset and the phone will wipe all the installed applications including the hidden ones.
Or download an antivirus for phones... it is more eazy this way
Try Dr Web light, can be found in Google Play. It should detect suspicious files.
As mentioned by Pete you should wipe all the data and factory reset your phone. It will be more effective than using any Antivirus or anti-malware app.