This app was mentioned in 2 comments, with an average of 2.00 upvotes
Watchville has a great internet-time feature. Use it along with a spreadsheet in Google Drive to keep track of things if you really want to get detailed.
My preferred method is to set it to atomic time using Watchville, and check it a week or so later to see how it's changed. Divide by the number of days it's been and there's your average loss or gain/day.
https://play.google.com/store/apps/details?id=com.north.watchville&hl=en
Nice! I use Watchville for my Android phone, it's on Itunes too:
https://play.google.com/store/apps/details?id=com.north.watchville&hl=en