Source code for Bangle.js App Manager and How To Use documentation needed - How to Launch Apps?

Sat 2019.12.28

https://banglejs.com/apps/
App Manager

ref: http://forum.espruino.com/comments/15038677/
From which I learned about the index to the Bangle Apps source code

https://github.com/espruino/BangleApps/tree/master/apps

Anyone know the location of the source? I would like to splice into the 'Settings' menu source, which doesn't seem to currently do, in order to launch other uploaded apps

. . . . or, . . .

Anyone have documentation on how the App Manager works?