First off, for reasons I do not understand, when I Deploy a release version of my APK (i.e., deploy to my file system), the apk is MyApp.MyApp.Signed.apk.
It is not signed (AFAIK). But it does download (i.e., copy from my file system to my phone which is connected to my computer via USB) and install to my phones OK.
When downloaded from my web site, I get a warning.
BUT when I create a real signed APK I get problems.
I go to Archive, Distribute, Ad Hoc, Save as. That seems to go smoothly, even though I'm unclear about the KeyStore. Still, that works.
BUT when I try to Download the app from my website, it doesn't download. Android reports it is downloading but nothing seems to be downloaded into the Download folder.
I have deleted the app, uninstalled it from Apps, cleared the cache, etc.
When I copy it from the Release folder, it installed without error.