Clean and Simple
I’ve tried all of the whole life gamification apps—all several of them—and have been using them since college (~10 years ago). It would be even better if it had a way to apply points from one task to multiple skills and a pie chart to visualize progress, but the features it does have are clean and honed in. I always think it would be cool to position skills into a hierarchy, where earning points in a child skill would also increase the parent skill’s level to a lesser extent.