You shouldn't need a plugin to enable web socket support. Instead use something like socket.io, which will fall back to XHR polling if web sockets aren't supported.
On Android, I'd also suggest using Crosswalk so that you have a consistent environment across all supported targets.
Make sure also that you:
* Modify your content-security-policy (CSP) meta tag to allow web socket activity (ws://)
* Make sure your config.xml whitelists your server
Tanks for the answer kerrishots.
As I said, the application wokerd on Android 4.4, so I don't think the problem concerns the CSP or the whitelist (anyway I already added an Access Origin tag before testing)
My other question is how to use socket.io in this context (PhoneGap Build) : do I have to add a link in the config.xml ?
1. Your server should follow RFC 6455 - The WebSocket Protocol.
2. Socket.io is a multi-transport library that uses web sockets when it can. If it can't, it tries other methods, which would require your server to handle those other options. There are Java servers that work with Socket.io out there.
4. There are other wrappers around the web socket API in the browser, or you can use it directly; I've had experience with Socket.io and it has fallback options, hence why I suggested it. But you don't have to use it if you don't want to. If you follow #5, you could just use the browser's web socket API directly. See https://crosswalk-project.org/documentation/apis/web_apis.html
5. On Android, use Crosswalk. This unifies the environment across all supported Android targets, which makes for much easier testing and debugging.