Note:
Pebble.appGlanceReload()is not supported in the Pebble mobile app and its callbacks never fire. Use the C AppGlance API from the watchapp instead.
The AppGlance C API guide describes how to set the
icon and subtitle shown alongside an app in the launcher with
app_glance_reload(), including the slice format, system and published
media icons, and the subtitle template string language.