Help Weird functioning of xperia z

[techsnew]

I removed the battery saver app since the phone was very hot when used with that app. Now , other apps start up automatically all of a sudden. Today, I could not pick up a call and the phone was ringing continuously. I was shocked to find another application , an online compass, was also running with the ringing. The phone was also very hot.

I removed the app immediately. My phone model is C6602. I recently updated the android version to 5.0.2, build no: 10.6.A.0.454.

Kindly suggest how to resolve this issue without re formatting.

Thanks