Homescreens that are declared certified in their manifest will have the delete button disabled in homescreen settings. Currently, both the new home screen and default home screen can't be deleted. I suspect they are both certified, because I pushed two new homescreens to the device, and the privileged homescreen had the delete button enabled while the certified homescreen still has delete button disabled. [Repro Steps]: Prereq: apply the new home screen 1. Tap Settings -> Home Screens -> Change Home Screen 2. Tap on New Home Screen name [Actual Result]: Delete Home Screen button disabled [Expected Result]: User can delete home screen [Build Info]: Build ID 20151006203020 Gaia Revision 0019347fbaedc9d54f2f3436fff17aeb22968174 Gaia Date 2015-10-06 16:41:48 Gecko Revision https://hg.mozilla.org/mozilla-central/rev/727d765a5ed81656d3a30724f5b70ba0bd17b9c5 Gecko Version 44.0a1 Device Name aries Firmware(Release) 4.4.2 Firmware(Incremental) eng.worker.20151006.194815 Firmware Date Tue Oct 6 19:48:22 UTC 2015 Bootloader s1

You can't delete built-in applications, pretty sure this is intended behaviour.

I see, since homescreens in marketplace will not be certified apps. Thanks.