Radiotechnika Sans Serif Font
This is a thin modern minimalist sans serif display font from designer Serezha Zhigarev, based on the original soviet letterings that have been used for a different UI solutions in industrial design.
Due to the compound of smooth curves and strong geometrics this font stands as a friendly for user but keeping the spirit of tough engineering. The font you want to trust to.
It comes with the basic cyrillic letters, and a simple set of additional symbols.