Poi LAB is a poi spinning simulator. It can be programmed to do thousands of different moves, from the simple to the super complicated. Isolations to 8 step caps to box anti-spin to... It's literally a very large amount of moves. There are downsides however, for the purposes of this free version, the poi act like clubs / sticks, they don't do pendulums right now. They will in the full version, but not in this version.
You can load one of 100+ patterns and then view them or modify them. These patterns come in two sets of terminology, VTG (Vulcan Tech Gospel) or OG (Old School). VTG is the default and the standard in North America. I prefer my OG terminology, cos I'm old. :)
In terms of modification, you can choose one of the pre-programmed patterns, load one in from your friends, or control different variables to create your own.
It displays a 2D representation of the poi move, to aid your spinning and learning. It has a fire trails mode: so that you can see what it'll look like before spending time learning it and a trails mode, mostly just because it looks cool. You can also slow down the motion of the poi to understand it better, or you can just view one poi at a time.
You can save your patterns as text via the clipboard, then either save them or share them.
There is a guide online here: http://tutorials.firestaff.net/wiki/index.php?title=Poi_Lab_Help
This simulator is supported by Ads or there is a full version that is 1.99 of the GBP. (in my country) Here's the full version: https://play.google.com/store/apps/details?id=net.firestaff.mcp.poilab.full