I really found it time consuming to create concept maps. I used MS Office to create the bubble concept maps for my ID Project: Ghost Hunting Scientific Method. When finished I converted them to PDF files and uploaded them to Google.
Here is my ID Project Concept Map:
and Scientific Method Concept Map Link.
Below you will see the Concept Map I created that provides connection lines between the instructional models of: A.D.D.I.E, PIE Method, A.S.S.U.R.E Model, and Gerlach & Ely Model. The concept map was created in Google Drawing. Personally I found Google Drawing was better to use when creating a bubble map.