Appetizers, Right?
This post is just one huge misunderstanding. When we first read it, we understood the OP to mean what sort of smartphone apps are worth spending money on. One commenter took apps to mean appetizers, which is why they went on about mozz sticks and spinach artichoke dip, which we think are also great.
To be fair, the OP should’ve been clearer when asking for apps. But we’re also in the same boat as the OP. What smartphone apps are so good that you’re willing to spend real-life money on buying them? We heard Flappy Bird was great, but you can’t get it anymore.