How would you know if someone was tracking you?
Flashing of a blue or red screen, automated settings, unresponsive device, etc. could be some signs that you can keep a check on. Background noise while making calls – Some of the spying apps can record the calls made on the phone. To be sure, listen carefully while making a call.
Can you tell if someone put a tracker on your phone?
Check your bills If there's a tracking app or spyware on your phone, it could send your data charges through the roof, as it's fairly common for such apps to use GPS to monitor your phone's location and use data roaming to report back to whoever's controlling them.