Mac (10000 programs)

Pros: Questions span entire history of the US. Hint function provides help when needed. Carefully researched questions. Three different difficulty levels.

Cons: Number of questions is relatively small. Free version does not include 'Hard' tier. Input method may not appeal to some. No competitive head-to-head options.

Pros: Fun app that's also useful. Several colour options available.

Cons: Not close to real life. Results may not look uniform across mobile devices due to display disparity.