Tapfish is an app where you can buy tanks, fish, and tank accessories. You start off with a green snapper, and you can earn coins by feeding and loving your fish,and Cleaning your tank. You can visit other people's tanks and take care of their fish toearn more coins. Fishbucks are a special kind of money you usually earn by leveling up. You can level up by earning expierence points. Then you can buy and sell fish, and unlock fish as you level up, like in paradise island http://paradiseislandhd.wikia.com/wiki/Paradise_Island_HD.