ReCal Sans is a browser-based customizer for Cal Sans, a free variable font by WORDMARK. Tune the geometric (GEOM), optical-size, weight, ascender and sharpness axes, remap the glyph-swap thresholds, and download a static TTF with your decisions baked in — free under the SIL Open Font License. The customizer needs JavaScript; the fonts it produces do not.
Comparison pages: Poppins alternative · Gotham alternative · GT America alternative