Great news everyone! We've spent the last few days cleaning some bits and pieces of the companion app, which today has been publicly released on Github! Not only that, but we've also put together some documentation detailing how to build it from source, and get it up and running on your phone. We hope to publish it into the Android Play Store in a not-so-distant future, so that installing can be even easier.
We have released as well, as a separate component, a Cordova plugin that we built ad-hoc for the WatchDuino companion app, but that we think it has a purpose general enough to be useful to others. It's a plugin that makes the phone notifications available to Cordova apps as events. We use it to listen to all of the phone notifications and pass them on to the watch. The source code is on Github as well.
'Cause sharing is caring :)