Today's Free App of the Day is Orrery
Originally $1.91

This is a beautiful and unique app. It is a digital version of an orrery, "a mechanical device that illustrates the relative positions and motions of the planets and moons in the Solar System." As the app will tell you. :)

You can change the orientation of the orrery by dragging with your finger. Pinching or spreading zooms out and in. Doubletapping on an object zooms in on it. Double tapping again brings up info from Wikipedia about the object. There is a sliding bar at the bottom of the screen that spins the galaxy and the objects in it faster or slower depending on where you slide it. It's somewhat disconcerting to see the earth spinning wildly at faster speeds. You can set it to see the relative position of the planets on a past date--the system does not rotate in this mode.

Warning for old folk like me for whom Pluto will always be a planet--it's not included in this. I loved this app, though I don't suppose I'll do much with it. Think of it as a kind of interactive reference book.

And I learned a new word. :D

14 of 17 reviews are four stars and above.

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.

Have fun!

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