I was very inspired by what Twitch have done with the UI of their app, especially for the text inputs, that I found clear and clean. Badoo was the second main source of inspiration. I really liked the white spaces used in the application, leaving a good place for purple to express itself as an accent color.
For the font, Work Sans allowed me to give a little artistic touch to the app, with its beautiful weight and type-writer inspired characters, while staying optimized for screens.
I can also mention the central place of photos in the application, with big ones for profiles and the swipe flow. Or the rounded and soft corners of the components, to offer a fun and playful interface.