I designed several UIs for 2getherAudio's audio/vst plugins. The UIs reflect various styles from vintage emulations to modern, flat, sci-fi, and futuristic designs. Feel free to check them out at - https://www.2getheraudio.com/

Style: Vintage emulation
Products: Cheeze Machine Pro, Ticky Clav 2 and Vinylla

Style: Sci-fi, futuristic
Product: Space Duck

Style: Modern Flat (almost)
Products: Snare Drum, Kick Synth and Clap Maker

Style: Hardware lookalike
Products: Rich and Rich Drums

In addition to the plugins, I also designed the editor/builder called Qubiq Structure that they use to make their products.