AppHarbor is an amazing tool for indie developers or startups that are just getting on their feet. To put it short, AppHarbor is the Heroku of .NET, being developer friendly, cost effective and performant.

Their platform has some nice features including the plugins (integrations with different services such as shared or dedicated RDBMS instances, document repositories, messaging queues, logging and monitoring services, etc.) that are extremely easy to use, and especially integrations with BitBucket and GitHub.

It's such a pleasure to work with the integrations mentioned, that whenever a developer pushes commits to the selected branch, AppHarbor automatically pulls, updates, builds, runs the unit tests and deploys. The cream of the crop is the fact that even the free tier supports this workflow which is practically a continuous delivery approach. And this makes AppHarbor perfect for startups and independent developers.

And, for established companies, I have to add the fact that their customer support is quite good.

With Cloud Endpoints you can create and deploy mobile backend in one hour or less. And it is free (until you need extra scale). I would not recommend to use Java - python is faster and has all new appengine features.

Pros: everything is in one place: task queue, cron, backend instances for data processing, datastore, mapreduce. Cons: you cannot easily move your code from GAE. Even with special 3rd party services.

With Cloud Endpoints you can create and deploy mobile backend in one hour or less.