> It would be nice to add other applications to the File Browser and Application List via their corresponding GUID.
The file browser shows you all of the apps on your phone that are browsable, if an app isn't there I can't browse it.
> Also it would be possible to search for apps in the marketplace to find those GUIDs without looking them up manually.
You can't browse the IsolatedStorage of marketplace apps, only sideloaded developer xaps.
> I'm currently not sure if it is possible to access the isolated storage of non-sideloaded applications via their GUID (never tried it, actually),
> but it should be possible to launch / kill them.
Yup, this would probably work, though I'm not sure why that is useful for anyone? I'm happy to add it, it just seems kind of useless since I can't enumerate the installed apps and would have to remember individual guids, the only benefit being that
you can launch them from the app (which is no faster than simply launching from the phone itself). If you have a reason why this is useful I'd love to hear it and then we can see about adding this in!