I think an application has been put on my phone that tracks calls, SMS, etc

[AC Question]

A third party is receiving web based information on my phone and texts are being sent to a mobile.
I have reset the device to factory settings several times, but how do I really know if this app is now gone? I have a suspicion and no proof so don't want to accuse anyone.
I just want to be assured that the technical app is gone ... I know nothing about operating systems and am not a developer. I am a lay person who feels unsafe.
I spoken to my service provider who cannot help me ...
I hope there is someone who can advise me on what to do.

Thanks

 

[Rukbat]

Just keep watching. If it happens again, reflash the ROM. How you do that depends on the phone, but if you post that (create a free account here, so we can keep the discussion in this thread instead of starting new ones for every question you have), someone can point you to instructions. (Or you could ask your carrier to do it.)

You'll lose everything - pictures, videos, texts, etc., so back the phone up (see Backing up an Android Device). Don't back up the apps - that's where things like that often get stored. Install them from the Play Store fresh. (Make a list of the ones you have, and take screen shots of your home screens [and back them up[, so you can set the phone up again without wondering where you used to have this icon or that.)