Small android app + related server that receives build status notifications from Jenkins.
The small java jetty server needs to be running (see ServerStartup.java) and your Jenkins needs the Notification Plugin sending out notifications to the very same server. This java server is basically used to store & synchronize notifications with the Parse service, which can then push them to mobile devices (among other things).
Once your java server is running, the app will automatically receive push notifications via the afforementioned Parse service. Creating a new user is optional. Some screenshots:
