10000 Hours lets you keep track of how much time you put into activities that are important to you.

You can set a goal of how many hours to reach before an end date and track your progress. My Activities shows which ones need your attention at a glance, and just tap an activity to see how you're doing on a progress chart.

This app is really easy to use and your data is stored in a database for reliability.

The app data is synced to your phone's account using iCloud or iTunes sync. In that way, if something happens to your phone, or you switch to another iPhone, your progress data is kept.