Self hosting instructions are also now available here: https://www.findmycat.io/docs/Hosting

This gives you the ability to host the cloud software on a small computer like Raspberry Pi so you can avoid cloud compute costs that occur if you choose AWS/Azure. 

Note that you will need some familiarity dealing with the Router GUI interface (it's pretty easy) to setup port forwarding. The instructions are device specific so please look up your model's instructions.