You could take a look at this: http://mmm.page/
Small(ish) community that is make cool stuff. The developer is really good with community feedback and pushing features!
All of our house cats are trained to do some special behavior like tap us with their paw or headbutt us to get fed. Not many people are impressed, most of them think the cats trained us.
We chose not to try this with the barn cat, however, because the barn cat thinks a really good interaction ends in a bite and "bite and get fed" is completely unacceptable.