On the toolbar you can manage your annotations.
To format text, tap and hold the Text Formatting icon [1].
To add a note, tap the Note icon [2].
To add drawings, tap and hold the Drawing icon [3].
To move the toolbar, tap and hold the drag handle [4], and move it to the new location. The toolbar can be relocated to either side of the screen.
To return to the previous screen, tap the Close icon [5].