Hurrah for me! Yes I realise that 50,000+ apps got there before mine but heh I am entitled to be a bit excited. It is called “Running Low”, and is available now for your Android device
<EDIT>
A few people have asked what it actually does so here is the blurb from Android Marketplace
Remember when you were supposed to be meeting someone and the phone died.
Remember getting home to "Where've you been? I have been trying to get call you!". Not your fault the phone was dead and you just didn't realise.
Well Running Low will message ahead and tell them "You're about to go offline"
Location optional
</EDIT>
Anyway whilst the issues I came up against while developing “Running Low” are covered already, elsewhere on the net I wanted highlight the PITA that is signing of your app.
The official android docs covering “Signing Your Applications” are here. IMHO Plusminus’ post on andxdev.org “Signing your apk/application for release (keytool,jarsigner)” does a better job of explaining key creation and signing than the official docs, and his is partly in German!
UPDATE
1. Hours after adding the app to the marketplace i checked my install of the app and found it had failed. Minor panic as I had to assume everyone trying to download it would get the same error of “package file was not signed correctly”. I double checked the signing process but all looked good then i read this post saying remove your dev version of the app before installing signed one from marketplace. I uninstalled the copy of my app that I had deployed during development, downloaded again from marketplace, and all worked fine.
2. I was a bit disappointed to see the 0 downloads on the Android Developer Console but supposedly Google are having some issues with the statistical reporting.