I'm looking to choose a mobile development environment to use to extend access to mobile devices for my existing GWT/App Engine web application. Codename One looks great in many ways and the programming model is very clear to me because of previous Swing, JavaFX, and GWT experience. My existing GWT application uses GWT RPC to communicate with the app engine server. That, coupled with it being very simple to use makes it my first choice for network middleware for my situation. However, I would consider changing to Google Cloud Endpoints or some other widely used open source solution for both my GWT application and the mobile apps that I plan to develop. I would like to have a solution that allows me to pass entity objects bi-directionally between the client and server to support the ability to update on the client and then store the updated object on the server. I'm looking at m-gwt/phonegap, as well, btw. I would greatly appreciate some guidance on what technical approaches would work in CodenameOne and GWT to communicate with App Engine, and hopefully meet my needs stated above. Thank you in advance for any comments/guidance.