Aileron is a Sans-serif typeface that is based on another font called Neo-Grotesque, which includes Helvetica. To differentiate it from the capital letter “I”, the designer has slightly curved the lowercase letter “l” at the end.
This makes it easier to distinguish the two letters. Also, the small dot shapes like “i” and “j” or the dot inside a circle, as well as the curved part of a clothoid curve, were intentionally designed to give a softer overall look.
You can get a free download of Aileron Font here. It’s in the TTF (TrueType) Format and you can use it for personal and commercial purposes without paying.

