The TSheets app does not run continuously, so it only uses a small percentage of your mobile device's battery power. The exact rate of battery used varies by device and app use.
95% of TSheets mobile app customers use less than 30 MB of data per month. That’s according to TSheets customer mobile data usage collected between February 2018 and April 2018. The same data showed, on average, TSheets mobile app customers use about 5 MB of data per month. You can check how much data the app is using on your iPhone by going to Settings > Cellular > TSheets. You can check how much data the app is using on your Android by going to Settings > App > Application manager > TSheets.