Click 'details' next to the red cross in the drop-down
Look at the log file
And it says:
ERROR: App suw's suw.settings.js is a JS file but isn't valid JS
If you view the file in the Web IDE you'll see there are some errors marked there too. The file may have failed to upload because it had syntax errors. Fix those and you should be good :)
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Actually, I have some idea that may help.
If you look at the top right of https://github.com/blogmywiki/BangleApps (or even the page you linked) there's a red cross.
And it says:
If you view the file in the Web IDE you'll see there are some errors marked there too. The file may have failed to upload because it had syntax errors. Fix those and you should be good :)