For my KFHD8.9, I got the
OtterBox Defender case. It's very rugged and adds a lot of bulk and weight to the Fire; which is what I want. I got this Fire primarily to stream videos when I'm at home, both indoors and outdoors. I wanted maximum protection in case it takes a spill while I'm lounging outside.
To improve its functionality, I added
1Mobile Market and
ADW Launcher. So far, all of the apps I've loaded from both Amazon and 1Mobile work just fine; and I've had no problems with scalability either.
I added 1Mobile to get apps that aren't available on Amazon: like YouTube, Google Maps, Nook, Aldiko, Kobo, etc. This app store is easy to add. Just go to its website on the Fire's browser and download the APK directly to the tablet. No computer or cables needed.
I added ADW Launcher (from 1Mobile) because I most thoroughly despise the Fire's carousel and its total lack of anything even remotely resembling app organization. With ADW, I get a stock Android layout and can easily organize my apps into folders.
Neither of these additions require root and the Fire is still stock. All in all, I'm very pleased with this tablet-case-market-launcher combo.