There is no font size to choose from.
1) The built-in font size is too small. You should have different font sizes to choose from for every aspect of the app; for “Checklist”, “Notes”, “Task”, “Subtask” etc. And also different font styles to choose from.
2) Another suggestion/idea; it would be nice to have the entire “Checklist” “Task” “Subtask” label or heading visible in all views, not just a portion of the wording, like in cases where the label might be a long one with plenty words, but the entire wording of the label visible at a glance, and not only when you tap on it to see and read the entire label on the next linked screen.