Re: What Frequency is used?
Fortunately the newest Android system allows me to lock out permissions in each app, and I lock out everything the app doesn't need to do what *I* want it to do. Permission to use microphone for an app that doesn't clearly need it? DENY.
This is EXACTLY why I purchased the WileyFox Storm recently, it'll be a long time before Android 6.xx becomes standard on handsets due to manufacturers refusing to patch or update vulnerable systems.
Cyanogen OS includes so many extra privacy features, more than even google provide in their latest version... and it's constantly updated.