Question
Would this use a large amount of mobile data?
Would having this running in the background use as much battery power as say Google maps (without ever having to display a map)?
Note:It's okay if the app is measuring in intervals (every 1/8 mile) if that would help reduce the data or battery useage...
Answer
Yep, you would be polling intervals/speed and saving those locally during a drive session then you would post those numbers back to the server for calculation. No need to show a map.