On Your IPhone:
1. Go to Photos App 
2. Select The Virtual Bib
3. Press "Edit" (Top Right Corner) 
4. Press the 3 dots on the Top Right 
5. Select "Markup"
6. Press the "+" in the bottom right on your screen
7. Select Text and move to Desired Place on Bib 
8. Tap the "Text" and select "Edit" from the black box Just above from where you tapped!

On Android with Google Photos 

Open a photo in Google Photos.

1. At the bottom of the photo, tap Edit (three horizontal lines).

2. Tap the Markup icon (squiggly line). You can also select the color of text from this screen.

3. Tap the Text tool and enter your desired text.

4. Select Done when you've finished.