This module just add full screen button for interactive tree view tab with webtrees.
This function was implemented in webtrees 2.1.8. So module is abandoned.
Same as webtrees#system-requirements.
Tested with 2.1.1 version and Webtrees Theme.
webtrees/modules_v4
directorytree_view_full_screen
For webtrees 1.7.x, you can use version 0.2.
For webtrees 2.0.x, you can use version 0.9.