ProntoForms - ProntoForms is a mobile business solutions application, converting paper forms onto any tablet or mobile device.
draw.io - Online diagramming application
mHelpDesk - mHelpDesk is a mobile field service management software.
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.
Forms On Fire - Forms On Fire provides a complete, customizable mobile forms and workflow system that is reliable and secure, works offline or online.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.