@dtarrant
in the myapp.apparmor you must insert the "video" and "audio" permissions (see the documentation).
the file myapp.manifest must copied to manifest.json .
so i tested this on my ubuntu-phone in terminal whith " click build ." ; then i have the myapp.click which can be installed by ut.tweak-tool or by using "pkcon --install ..." . After this you can test your application before uploading to the store

the last opened tab (maybe a unwanted link) cannot be closed via "unwanted tab X" .
i always must select another tab to close this.

after browsing a time the morph browser terminates suddenly ( crash??) .

@ukphil YES !!! this worked also for me!
Months of insecure (is there any virus?? that boots my device twice ???) are past!
thank you very very much !

< " it is a corrupt media database - "/userdata/user-data/phablet/.cache/mediascanner-2.0/mediastore.db" or /home/phablet/.cache/mediascanner-2.0/mediastore.db.
I deleted this db and the double boot/shut down did not happen.">