Илья Бирман. Пользовательский интерфейс. Электронный учебник
Visual design rules you can safely follow every time
UI cheat sheet: Spacing friendships
System fonts don’t have to be ugly
Phosphor Icons
Method 3 - Desktop Blocks
Laws of UX
GUUULP! 3d Illustration Kit
Funny and colorful 3d illustration kit for any type of project
Each icon is rendered in a huge resolution scene. Create some crazy stuff!
Chat UI Kit - Messaging Interface Design