Ongoing support / free app?

Hey, this is looking like something that would be useful for me and my partner to have in our offices. But there are a few things I wanted to check.

1. Can multiple calendars get synced within the app or would you have to have them synced prior to them getting to the app?
2. Is there plans and the money for ongoing app maintenance? Not necessarily new features but just availability of the app for new phone OS'
3. Will the app remain free for the life of the product?

Thanks!