Inter UI is a free font family designed by Rasmus Andersson for featuring an excellent readability on computer screens. Typeface comes in 4 weights (regular, medium bold and black) and includes italic style. It works great for English-language text, and pretty well for other Latin and Cyrillic languages.
Inter UI is very similar to Roboto for many aspects. The project started out in late 2016 as an experiment to build a perfectly pixel-fitting font at a specific small size (11px.)
The idea was that crafting a font in a particular way, with a particular coordinate system (Units Per EM), and for a particular target rasterisation size (11), it would be possible to get the best of both sharpness and readability.
You are free to use this font in almost any way imaginable. Refer to the SIL Open Font License 1.1 for exact details on what the conditions and restrictions are.