Add Smartphone Integration

[casaout]

The idea is to (at some point) have a smartphone app (for iOS and Android) that lets users access the insights/retrospection and enable additional trackers.

The additional info that could potentially be tracked (if users are interested in it) is:

• what someone is doing when IDLE on the computer (maybe using the phone)
• location
• work unrelated stuff (social networks, private email, etc.)
• movement/physical activity (as most people carry their phones with them everywhere)
• background noise (from microphone)
• light (light sensor)

[casaout]

Erik Bjäreholt gave me a few pointers. tl;dr: Android is possible, iOS is not possible as only aggregated data can be accessed at this point....

Yes, Android is doable for sure.
For reference, here's our implementation in aw-android: 
 - https://github.com/ActivityWatch/aw-android/blob/master/mobile/src/main/java/net/activitywatch/android/watcher/UsageStatsWatcher.kt

iOS is a longer and more complicated story. You can read up on the history and some of our attempts here:
 - https://github.com/ActivityWatch/activitywatch/issues/751
 - https://forum.activitywatch.net/t/ios-application/1357/4
 - https://developer.apple.com/documentation/deviceactivity/deviceactivitydata?changes=latest_minor