Sometimes the simpler the game the better. Traffic Rush is such a game, popular with youngsters as well as older gamers. You control a busy crossroads (a.k.a intersection) with a series of vehicles moving at different speeds. You can pause them, speed them up, but have to stop them crashing. It starts off easy, then, as the traffic builds up, gets very tricky.
The graphics may be basic, but the gameplay soon draws you in.
Normally a tier 1 69p (99c), it’s currently available for free from iTunes here.