After a long wait, APRSdroid has finally been released on the Droid App Marketplace. It’s actually the first app I have purchased! (You can get the free release here, though I purchased mine to encourage further development.)
Everything went smoothly- I had my APRS-IS password (search “callpass APRSdroid” or “callpass APRS” for more details) and entered it in with my callsign. I configured the server to “noam.aprs2.net” for North American users, instead of the one entered already for Europe.
Once you have something like this configuration, it should be a breeze to use. I’ve not yet tried it driving long distances- let you know how that goes when I do.