How to delete watch face with all data?

Use Garmin express to delete it

It looks like it's not available on Linux.

Is there a way to do it on Linux?

If you can't use the on-device Connect IQ store app, you could also:

- determine the "basename" (filename without extension) of your sideloaded app. e.g. If your sideloaded app was named AWESOME.PRG, then the basename is AWESOME

- delete all files in \GARMIN\APPS\DATA and \GARMIN\APPS\SETTINGS which have the same basename as your app. e.g. If your sideloaded app was named AWESOME.PRG, then delete \GARMIN\APPS\DATA\AWESOME.* and \GARMIN\APPS\SETTINGS\AWESOME.*

This won't delete the app itself (ofc on newer devices, the app PRG will never be available in the user-accessible file system), but it should delete the kind of persisted data that you're looking to get rid of.

Note that on some watches, the app filename will be truncated to 8.3 format (i.e. 8 chars for basename, 3 chars for extension), meaning that AWESOMEAPP.PRG (for example) could be truncated to AWESOMEA.PRG. If this happens, hopefully it will still be obvious which files in APPS\DATA and APPS\SETTINGS correspond to your sideloaded app.

@FlowState I'll give you kudos for the effort, but I'm not sure all that will actually be sufficient as I've had cases where the prg itself did not update properly if I didn't delete it with express first.

I think OP has 3 choices;

- install windows and use garmin express

- Continue to use linux, Install wine + Garmin express. USe Garmin express to delete the sideload

- Instead of sideloading do an upload as a beta app into the store and use this way to test the app

What about the 4th choice of using the Connect IQ store app on the device itself to uninstall the app? This works for me.

The only possible issue here is that OP's watch is too old to support the on-device CIQ store.