The website is great for drawing surprisingly! It doesn’t have a fill-in bucket, but that’s due to it being infinite probably. If you’re looking for a collab site for doodling with your friends, that’s what you’re looking for! If you have any ideas on what could be added, you can always contact the devs, they usually respond and are super helpful :).
Update: I am happy to edit my review to inform everyone that now Whiteboardfox offers a bucket feature!
It is very good for doodling random ideas! make sure to have fun and keep being creative! It is down sometimes though ;-;
Xmind - Xmind is a brainstorming and mind mapping application.
Witeboard - A real-time whiteboard for your team. No signups required.
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Mural - MURAL is a visual collaboration workspace for modern teams.
MindManager - With MindManager, flexible mind maps promote freeform thinking and quick organization of ideas, so creativity and productivity can live in harmony.
Scribble Online Whiteboard - Scribble Online Whiteboard is an advanced collaborative whiteboard solution that allows you to draw the sketch using the web-based or mobile platforms such as iPad/iPhone and Android.