please please please please please put out the invoicing addon.
an iphone user for many years, i have been interested in switching to android, but couldn't for one important reason: your app. i got an android phone the moment i saw that your app was available. ut oh, there's no invoicing option. now i have to keep my iphone available to do billing, but it's gonna take backing up and restoring twice to make it work.
it also dawns on me: is the android version keeping invoicing info in the database, or have i lost it now that i've restored my backup to a version without invoicing? that's a scary thought. will have to test this later today.
anyway, i absolutely love the app, and am psyched it's now available on android. can't wait for the invoicing module to arrive!