Does Amazon need a reason to give away free premium apps? I doubt it. Through Saturday (November 1, 2014) you can get the 40 apps listed below for free. These apps normally range in price but all normally cost money.
Remember if you select the apps on Amazon's website they will stay in your cloud but not take space on your device unless you want to download it. Some of the apps will work on all Android devices while others will only function on Kindles.