If you like your sniper games simple and basic then Super Sniper Shooting is the one for you.
It has three levels - Basic, Intermediate and Advanced - which all are pretty easy. You tap the screen on the target you want to shoot and 99% of the time you hit them. I'm not sure if you can complete a level, as each time I just keep shooting until I die and that's when the game ends.
It won't provide much of a challenge for serious gamers, but if you want to waste some time, try Super Sniper Shooting.