MAXQDA - a professional software for qualitative and mixed methods data analysis
draw.io - Online diagramming application
NVivo - Buy NVivo now for flexible solutions to meet your specific research and data analysis needs.
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.
QualCoder - A very complete Free and Open Source Software (FOSS) Computer-Assisted Qualitative Data Analysis Software (CAQDAS) written in Python. It works with text, images, and multimedia such as audios and videos.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.