Today's Free App of the Day is DoubleTake
This is a golden oldie--I got it in 2012, though it might have been a Free App of the Day since then.
It's a well-reviewed Concentration-style game. I haven't played it recently, but the current reviews by some of the top reviewers are quite good.
83 of 122 reviews are four stars and above.
Compatibility of apps varies. To tell if an app works for your Fire tablet or other Android device registered to your Amazon account, click on the above link and look on the right side of the web page for the "compatible devices" link.
Also check out the other digital deals from Amazon, including great deals on MP3s and videos: