Disclosure, I work for Zipline Games on Moai Cloud. Moai Cloud (http://getmoai.com http://getmoai.com), while focused on enabling backends for mobile games pro

Disclosure, I work for Zipline Games on Moai Cloud. Moai Cloud (http://getmoai.com http://getmoai.com), while focused on enabling backends for mobile games provides some of what you describe. We use mongo on the backend to provide schemaless storage and are building out a set of RESTful apis. Additionally if you need to you can write and run your own custom code on the server.