PowerSchool - PowerSchool provides a K-12 education technology platform for operations, classroom, student growth, and family engagement.
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.
Clever - syncing between education applications for K-12 schools
draw.io - Online diagramming application
Claroline - Claroline is a collaborative eLearning and eWorking platform.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.