Roblox PSD UI will take a .psd file and convert it into a format that can than be built in Roblox Studio. There are some limitations and things to be aware of so please see the limitations section ...

Roblox has opened a new beta that'll allow creators to go and stylize their UI like never before so their games truly pop. ... Take, for example, the “User Interface,” or UI.

In a new blog post, the team breaks down everything that’s going on, including how players can use new features on the games UI to make playtesting certain things easier than before.