Working on something similar. Currently supporting Android (draw/view) and HTML5 (view only, mouse zoom/pan).
https://play.google.com/store/apps/details?id=com.writelive
Small showcase:
- vector graphics/drawings created by freehand / writing http://write-live.com/d/dba21681-8d3f-4fbe-8b4b-e5c1983df934
- handles more complex drawings: (give it time to load) http://write-live.com/d/7fce10bb-bc39-43d4-a7f1-6bd0d60b9550 http://write-live.com/d/8f9b7846-a7b9-4e5c-b704-dad9aa87d14e
- unlimited* levels of zoom http://docs.write-live.com/WriteliveServer/webview.html?d=34...
- Drawings are stored in the cloud, and can be accessed by multiple devices simultaneously: co-drawing, draw on a tablet, view on tablet / web http://write-live.com/d/538254c5-7d31-41f2-83bb-bcd0a7cee7ab