Today's Free App of the Day is Weather Ex
This is a weather app which uses data from the Weather Underground. However, the reviews today are almost unanimously negative, citing advertising and privacy concerns. So, there's a bonus pp (in addition to the Weather Underground app linked above, which is not compatible with the original Fire).
6 of 25 reviews are four stars and above.
So we have a bonus pick: AccuWeather.
I use this one a lot, it has a great range of services and can be upgraded to a Pro version for 2.99.
These apps are compatible with the original Fire and with my Fire HD 8.9" 4G. To tell if an app works for your Fire HD or other Android device registered to your Amazon account, click on the above link and look on the right side of the web page. Amazon will tell you if it will work with your registered device.
Also check out the other digital deals from Amazon, including great deals on MP3s and videos: