you use google play to get a URL, then paste that into the above downloader link then press the buttongs on screen to gernerate a downlaod link & to actually fownload.
I got the Kobo reader app that way , for my HDX, & Id recommend trying that.
you should not need to have a google tablet linked to the store. it may be helpful to have a google account though, & to be signed into google chrome.
in KF settings you have to tick
allow apps from unknown sources.
the move the downlaaded instllers onto your KF by USB or via dropbox or similar.
Amazon app store does NOT have alkido, the only reader I ever found in their store was moon+ free
so for alkido, I fiind it in the play store, then copy the URL, which is
https://play.google.com/store/apps/d...droid&hl=en_GB
then I paste that into the app downloader page ( link above) & follow the instructions.
this gives you a clean copy of the app, but the method does not work for paid apps, only for free ones.
and you don't get automatic updates for apps sideloaded this way. You have to manually check & repaeat the process to get any later version. Play store will show date last updated if you scroll down to additional information, below the reviews: e.g for Alkido that was last updated 28 January 2014