With PDF Reader Pro, you can add text annotation as desired, or change the text opacity, font, color, or other characteristics using the drop-down lists and buttons.
1. Tap on an existing text annotation to pop up the quick menu and press ;
2. Slide the bar to adjust the font size;
3. Tap on the drop-down list next to Aa to change the font type;
4. Select a new font from the font list to change the font of the text annotation.