Xero by Rob Barba of Megami Studios is a free rounded geometric sans serif with broad curves and clean, open forms. Its strokes change gently in width, keeping the lettering soft rather than strictly mechanical. The rounded ends are especially noticeable.
Technology and contemporary lifestyle themes suit its streamlined shapes, making it useful for app branding and product packaging. The neat circular forms also fit music graphics and event posters with a clean, upbeat direction. Across those settings, the repeated round edges can echo buttons, icons, and diagram shapes.
Xero is an intentionally loose creation of a humanist font. Played rougher than its counterparts Helvetica and Arial, Xero works well for those who want to go that route but don't want the sharply defined lines of others in the humanist family.