Amazon Appstore Is Not Android Market
Amazon's Appstore effectively replaces Android Market. Many news apps are available to correspond with the Kindle Fire, but often times, the apps in Appstore are missing or out of date compared to Android Market.
Why is this the case ? Amazon's Developer FAQ clarifies:
"For your app to work on Kindle Fire, it needs to be compatible with the device's specifications. At a high level, it must be optimized for non-Google Mobile Services (GMS), Android 2.3.4 (Gingerbread), and a 7" screen with a resolution of 1024 x 600. Your manifest should specify support for large screens. Your app cannot require a gyroscope, camera, WAN module, Bluetooth, microphone, GPS, or micro-SD to function. In addition, your app must not be a theme or wallpaper that manipulates the user interface of the device. As with any other app submission to the Amazon Appstore for Android, your app will also need to comply with our Content Guidelines.
This explains the lack of a Skype app, since you need a microphone and camera for VoIP. That doesn't mean you can't use Skype for instant messaging. But unfortunately, Amazon simply won't let you install it.
Sometimes the Kindle Fire uses older apps because newer ones aren't yet certified. For example, the latest version of Flash for Android is 11.1, but the Fire is limited to 10.3. Getting better performance necessitated installing Flash 11.1 manually.
Unfortunately, getting around this obstacle could involve rooting your device. If you're not familiar with the process, it can render your tablet unusable. However, if you have a second Android device, you can generate an APK and install apps without rooting. But first, you need to enable "Allow Installation of Applications From Unknown Sources" under Settings>Device (see Appendix B).
It's both cumbersome and time consuming to back up and transfer APKs from another tablet. Plus, you can't install applications on the go. That's why I rooted and installed various Google APKs directly onto the Fire, giving me access to all of the Google apps that Amazon chose to strip out: Android Market, Books, Voice, Maps, Google+, Reader, Gmail, Street View, YouTube, and Talk.