We made an app that analyzes your driving behavior and generates a score for it:
One one of the screens you can see score circles in blue/orange/green/red (click to enlarge):
When you click on one a pop up comes giving more details about the specific score.
What we're trying to figure out is a way to make it clear graphically to the user that the circles are clickable, so far we've looked at 3D type icons with bevel/shadow but haven't been able to find the right ones.
We're not married to any particular way of doing it, there doesn't need to be circles at all, just looking for solutions that jibe with the clean/minimalist look of our app.