Is it difficult to include the ability to modify font size within applications? ...perhaps in some pref menu?

I understand that buttons and list entries need to be finger-friendly, but I am consistently puzzled why the font size has to follow? In playlists, for example, one app displays only one line with band then song name. A really long band name makes your song name disappear into the "...". Same rant for the schoolwork tracker app: A word like "English" can't even fit in the space allotted because the standard list font seems to be something 64 point: "Engl...".