Move tool (SPACE): The move tool lets you move the board around.
Right clicking will reset the zoom and position of the board.
Holding click with middle mouse can also move the board around.

Rotate tool (NONE): The rotate tool lets you rotate the board.
Right clicking will reset the rotation of the board.

Inkdropper Tool (TAB): Allows you to pick a color off the board. By default, after holding TAB to use the tool, then releasing, you will return to your previous tool. This behavior can be disabled in the configuration.

Select Tool (S): The mouse icon symbol is the select tool, it lets you select and alter lasso or rectangle regions of the board.

Eraser (E): The eraser tool erases brushstrokes from your current layer.
Right click toggles erasing on all layers by default.

Text tool (T): The text tool lets you type on the board, with a variety of fonts. Right click to change font.

Line Tool (L): The line tool allows you to draw straight lines.
Hold SHIFT to snap the line to 45 degree angles.

Rectangle Tool (R): The rectangle tool lets you draw rectangles. Hold SHIFT to snap to perfect squares.

Ellipse Tool (P): The ellipse tool lets you draw ovals. Hold SHIFT to snap to perfect circles.

The Fill tool (F): The bucket lets you fill in outline regions. It won’t fill very large regions to protect from people filling the entire board accidentally. So, if the region you are trying to fill has any gaps in the lines, it may not fill.

Blend Tool (A): The blend tool allows you to blend bordering sections of color.

Pixel Brush (X): The pixel brush lets you draw perfectly square regions of the board.
The grid can be toggled on and off on the side menu.

Custom Brush (C): The custom brush allows you to upload images and use them as a brush on the board.
You can also directly use regions selected with the select tool as an image.

Every tool has its own set of tool options, and some have unique properties,
These options are found right below the user list, on the far right:

Size: Defines the size of the tool being used.
Opacity: Affects how transparent the current tool’s effect is.
Blur: Blurs the current tool.
Smoothing: Turns on a smoothing algorithm to help compensate for jagged lines, caused by lag or sensitivity issues.
Spacing: Causes the current brush to turn on and off intermittently, can be used to make dotted lines.
Mode: Changes the current blend mode of the selected brush, only available in rooms with one layer.

Pressure: Tablet pressure – Currently only functions well on Google Chrome or the downloadable Desktop App.
All Layers: Causes the tool to affect all layers of the room, instead of just the selected layer.
Right Click: Defines the functionality for right click, which has different possible effects depending on the selected tool.
Cursor: Defines what cursor icon is to be displayed with each tool.

The Custom brush has a few more custom options than other tools:
Tint: Tints the brush image with your current active color.
Random rotation: Randomly rotates the brush image with each use.
Gallery: Opens a gallery with several pre-made brush options you can choose from.
Customize: Allows you to edit the current custom brush image, as well as save the image, or upload a new one to replace your existing brush.