While not exactly in the cloud and an Android app, it would facilitate I believe the following would facilitate what you are looking for without giving up control to Google Docs. It would also be accessible to those with iOS or Android.
What one of the organizations I am involved that heavily uses maps we did the following:
- We setup a basic hosted Wordpress site.
- We go the program Maps Marker Pro
- We created plots, overlays, and imported courses and other information from GPX files and did not have to convert anything into Google Earth format.
- Additionally if you want the maps to be private you can get something like PMPro (which we use) or S2Member to require login and current membership to see the content.
Again, while not an app.. we can from an iPad or Android tablet via the built in browser DURING an event add a new marker directly from our iPad and so participants when they refresh may gain additional information. You can add marker and lookup a location
You can also use the short codes it includes and with add pre-staged / timed posts using word press with additional clues (which if they are also email/Facebook/Twitter subscribers could get notification).
So basically we retained control of all of the map data, increased our tool set, and use public maps to create our own data overlays. The one thing is I do not recall it calculating distance of a course.. but I could just be forgetting.
The one feature it does not directly have (as of v2.1) is Add My Current Location from a web browser on your iOS, Android, or GPS enabled PC device. I use MotionX GPS to get tracks on iOS to do that then import it into Maps Marker Pro which in the field is a bit complicated but once back is very easy, or I use a variety of other GPS apps to just get my current GPS coordinates and then create a marker via the web interface right on my device.
OpenStreetMaps itself does not allow you to put overlays itself on it, and Google Docs does with some constraints but is pretty good for address lookup when importing a bulk number of addresses like from CSV.