The Text Size Change Function is available for IOS ver 6.9.0(above)/Android ver 6.7.3(above).

You can increase or decrease the font size of an Event Title on the Monthly View.

 There are 5 types of font sizes: Smallest / Small (default) / Medium / Large / Largest.

 The font size can be set from the Application Settings.

-Tap  'three parallel horizontal lines' on the upper left corner.

-Tap 'App settings' 

-Tap 'Text Size' and change