It depends if your app is using a lot of proprietary AppEngine APIs / features. If yes, then you will have to rewrite at least some portions of the app.
Due to the recent AppEngine pricing changes, I moved my app - Review19.com - away from GAE. I had to rewrite it entirely because I used a lot of AppEngine specific APIs.
There are other open source options that "replicate" some of the GAE APIs, but none of them claim to production ready.
Due to the recent AppEngine pricing changes, I moved my app - Review19.com - away from GAE. I had to rewrite it entirely because I used a lot of AppEngine specific APIs.
There are other open source options that "replicate" some of the GAE APIs, but none of them claim to production ready.