It is possible, but difficult.
For the Mac app store, you need to properly sign the app and submit it.
You must make your runtime a one file app, so you need to bundle it in an app (e.g. AppleScript one).
Than copy the database on first launch to document folder of sandbox and open it with the FM runtime.
A lot of hassle.
Thank you for your reply, Christian. Much appreciated. Just wondering, has anyone actually done this and have their runtime currently approved and available on the Mac OS X App Store?
I've googled similar questions in the past, and the links point to one person (literally one guy) who said he had a runtime approved for the Mac OS X App Store, but that was years ago, and the links to the actual application don't go anywhere or were expired. Either that or Apple then removed it from the Mac OS X App Store. Not sure.