Is combu flexible enough (or easy enough to extend) to support app updates?
I would like to pass an app ID and have combu return a value (timestamp). It would also need to support returning a file URL for an app ID.
I would also need a way of returning a list of supported app IDs.
Also, how hard would it be to expand to support paid user accounts, with a service like Stripe?
Sorry, I don't understand your question about "app updates" and "app ID", but extending Combu is pretty easy. For example to create a new database table you only need to create the associated class inheriting from a base class (with public variables called exactly like the fields in the table) and add your Load/Save/Delete methods with the respective SQL statements (like the core classes do), include the class file in api.php, create the new web services which interact with the class and finally add to CBManager in Unity all the methods which call the new web services.
Of course, extending Combu requires knowledge of both PHP and Unity C#.
About the support for payments, you'll need to create your own web services that interact with the provider (for example Stripe or Paypal), but if the provider requires to redirect to its website to login a user then you'll need to create also the returning web page that will interact with your database tables to set the proper data (items purchased, etc).
FRANCESCO CROCETTI @ SKARED CREATIONS