I remember going to a conference for developers a number of years ago and they talked about how programming one day would be more like using Visio then using Visual Studio. Popfly in my mind is one step closer to that goal. Really it achieves this for every day users being able to create web mashup applications.
Well to make it easier I created a couple of shared blocks for doing actual logic. One is called Eval and the other Math. Both blocks are shared so anyone can use them. They are fundamentally simple but provide the ability to add logic between blocks.
If you have a Popfly account just search for 'Eval' or 'Math' and you should be able to find these blocks.