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.
Morpholio Trace - Morpholio Trace is widely called to be the dream software of the designers and architect.
draw.io - Online diagramming application
DWG FastView - DWG FastView for Windows is a lightweight dwg/dxf drawing viewer and editor produced by Gstarsoft, no need of dwg format conversion, vector graph magnified without distortion and full compatible with AutoCAD DWG/DXF.
Visio - Simplify and communicate complex information using data-linked diagrams.
Drawing Desk - Drawing Desk Draw Paint Color, Doodle and Sketch Pad created and published 4Axis Technologies for Android and iOS devices.