Native support for H5P was recently added in Moodle. H5P videos do not work in fullscreen mode on Moodle Mobile (tested on both Android and iOS), while they work on Moodle Desktop.
This could be because of an Ionic v3 bug?
Note: H5P doesn't show fullscreen button in mobile app due to a bug. Comment out line 39 in embed.php in H5P package to display fullscreen button in Moodle mobile (phone + desktop).
Video sample. Video stops playing when fullscreen button is tapped.