This issue needs to be tested with the Moodle master branch. In web, login as teacher in a Moodle with master branch and create 2 pages with description and different Appearance options: one with description and timemodified disabled, and another one with both things enabled. In the app, open those pages and check that the behaviour matches Moodle web: the description is displayed only if the setting is enabled, and the same with timemodified. Check that timemodified matches the one displayed in web (please notice you could be in a different timezone than the server). Now create a page in a 3.3 site. In the app, open it and check that the timemodified is displayed.