Controls

Add new vertex - Click vertex, then click empty space
Connect vertices - Click vertex, then click another
Remove vertex - Right-click (tap-and-hold) vertex
Remove edge - Right-click (tap-and-hold) edge
Zoom in/out - Scroll wheel (pinch-and-zoom)
Pan - Click empty space and drag
Move vertex - Click vertex and drag

Software contributors

David Cushing et al.
Harry Richman
Includes the graph visualisation software cytoscape.js (MIT Licenced).