Open the PDF in Acrobat on Android and select Edit PDF from the bottom menu.
Select Add text
and tap on the document where you want to add the text.
In the text box that appears, enter your text, then use the handles to resize it.
To change the text color, select Color picker and choose a color from the palette.
Select Text size and drag the slider to adjust it.
To move the text box, long-press it and drag it to the new location.
Use the Undo or Redo options from the top menu to revert or restore the changes.
Tap anywhere on the document to finish adding the text.
Select the checkmark in the top-left corner.