Flowchart.js might be a bit more popular than Diagramo. We know about 1 link to it since March 2021 and only 1 link to Diagramo. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Dynamic Draw is portable and runs on Windows. Caligra, Diagramo or Umbrello for Linux. Source: about 3 years ago
What problems do you have with all the existing options (just a couple links I picked from a google search)? Source: almost 2 years ago
Modelio - Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI.
Code2Flow - An easy solution to create product flows.
UML Designer - UML Designer provides a set of common diagrams to work with UML 2.5 models.
DIagrams Through Ascii Art - Java command-line tool to convert ASCII diagrams to bitmaps.
Yakindu Statechart Tools - Discover YAKINDU Statechart Tools – a free statechart tool for the specification and development based on the concept of state machines.
Asciio - Perl application to draw ASCII diagrams in a simple, modern graphical interface.