Bismillahir Rahmanir Rahim.
Assalamu 'alaikum wa rahmatullahi wa barakatuh.
You can bookmark any page or even a specific ayah on the page. Only one bookmark can be placed per page.
To bookmark a page
Simply tap the ribbon indicated by the arrow to bookmark the page.
To bookmark an ayah
Tap and hold the ayah you want to bookmark and an option menu will appear. Tap the Bookmark Ayah option as indicated to bookmark an ayah.
To go saved bookmarks
Tap anywhere on screen and the bottom menu will appear
Tap the bookmark option in the bottom menu as highlighted below
Tap any saved bookmarks to go to that page.