The user interface or UI, in the industrial design field of human–machine interaction, is the space where interaction between humans and machines occurs. The goal of interaction between a human and a machine at the user interface is effective operation and control of the machine, and feedback from the machine which aids the operator in making operational decisions.
Whether you’re creating a desktop, mobile or web applications you need at some point to design the UI to attract users more. If you are out of ideas or working on a limited budget you can always use a ready made UI kit for your project. There’s a lot of free UI kits out there designed and shared by awesome designers, Here’s a list of 35+ free UI kits for your next project.