All data provided to Loop Habit Tracker is only stored locally in your device. Loop Habit Tracker does not upload your data anywhere. The developers of Loop Habit Tracker do not have access to your data.
Your data is not shared with any 3rd parties. Loop Habit Tracker does not include any advertisement libraries or any 3rd party tracking (analytics) code, such as Google Analytics or Facebook SDK.
If you have activated "backup & reset" in your phone settings (Settings / Backup & Reset / Back up my data), you should be aware that Android itself will periodically save a copy of your phone's data in Google's servers. The developers of Loop Habit Tracker do not have access to this data.