Unibill is getting really popular but the documentation and tutorials are for more advanced programmers.
A very useful action would be too get the variables for the in app purchases you set in the unibill editor.
Like if I create an in app purchase of 100 gold, I want it to be able to update my global variable "Money" I set in playmaker.
Some actions for unibill would be awesome because I can't figure out how to use it correctly and update my variables I set with playmaker.
Here is the link to unibill
https://www.assetstore.unity3d.com/en/#!/content/5767