You have what amounts to a tiny super computer in your pocket, and what are you doing with it? Hmm? App Habits will track which apps you're using and when so you can get the low down on exactly how you're wasting time with neat graphs. It will also use this data to surface apps you might be interested in based on the time of day.
App Habits has a clean holo UI with swipable tabs. The first one is where you'll see the top five apps for each day, and the second shows the top apps overall. The app automatically hides system processes, but you can add anything to the ignored list you want. For example, the Google Search app shows up very high on the list if you're using the Google Now Launcher.
All this data is used to help you visualize what you're doing with the device. It shows you which types of apps are getting the most screen time and includes a "launch pad" with app shortcuts that match your usage pattern. There is an optional notification with the same app shortcuts as well. App Habits seems to get the job done at first glance, so check it out.