How to pick a Typeface for User Interface and App Design?

TL;DR: Make the Il1 coe test to check whether a typeface is suitable for functional text. Il1 should be easy to distinguish and the apertures of c and e should be open.
Il1 coe
Il1 coe
Il1 coe
Il1 coe

Oliver Schöndorfer makes some points in his article “How to pick a Typeface for User Interface and App Design?