There is a free version available here: https://play.google.com/store/apps/details?id=com.bytesculptor.fontsize
Do you prefer a big font for better readability?
Do you prefer a small font to have a better overview on the screen?
Do you prefer both and would like to change quickly?
The Android system has 4 fixed sizes only. With this app you can resize the font from 65% to 250%.
► Shrink, enlarge and adjust the font size of your phone with one click
► Save unlimited font sizes, sort them by size or added order
► See a preview of the font size
► No phone restart needed after change (Android 7 and up)
► Works on smartphones and tablets
To use this app you have to agree to write system settings. The app will prompt you for permission on its start.