Design

I want to make some quick designs for a mini-app. I have a rough idea of how I want my design to function.

But I don't know where and how to start with the design, is there an app or tool that can let me quickly draft out/imagine a design and let me edit it on the fly?

Been using Figjam for whiteboarding! Just having a bit of a hard time trying to make the jump from whiteboard/ wireframe into designs that I think would fit the app. I'll give it a try, thanks!

Try https://www.figma.com/figjam/ or https://excalidraw.com/