Aven is a highly readable free sans serif font that comes with 5 font weights. It was modified from another popular free font called Maven Pro. Few font features were tweaked, mainly on the terminals and joints to improve the overall visual balance.
In the end, the characteristics of the original design were retained. You can download this font family for free and use it on any projects. Kudos to the designer Lecter Johnson on putting effort into the modification of the font.