Fontest is a free typography tool developed by No Allegiance that allows you to preview how your favorite fonts are rendered on Android. The app comes with six high-quality fonts and also allows you to add your own TTF and OTF fonts.

One of the best features of Fontest is its smooth font resizing capability, which allows you to easily adjust the font size to your liking. Additionally, you can customize the display text to see how the font looks with different words and phrases.

Another useful feature is the one-tap switch between uppercase and lowercase text, which can help you quickly determine how the font looks in both cases.

Overall, Fontest is a handy tool for anyone who works with typography on Android. It's easy to use and provides a quick and accurate preview of how different fonts will look on your device.