GestureSign - Create and assign touchscreen gestures to actions on a windows tablet.
draw.io - Online diagramming application
Tablet Pro - Tablet Pro is a futuristic mix of familiar tools adapted for touch devices.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
MultiSwipe - Custom touchpad and touchscreen gestures
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.