NASA has just published their 2017-2018 software catalog and it's a good news for all of us. It lists many apps, code libraries and tools that anyone can download and use. Yes, most of the items are indeed related to aeronautics and space-related stuff but there are quite a few of them that may interest laymen and curious people.
Here is a list of apps and programs that you can try easily:
If you are interested in exploring and observing the planets and solar system, NASA has it here. There are Global Reference Atmospheric Models for Earth, Mars, Venus and Neptune and Titan. These models are not toys; rather they provide information about the exact pressures and temperatures in those planets.
To get some more practical experiences, you may try the Worldview Satellite Imagery Browsing and Downloading Tool, which is a way to navigate through the huge pool of fascinating Earth imageries coming directly from NASA satellites. You'll get the latest shots as early as 4 hours after they're taken. Captivating, isn't it?
NASA has released an iOS app named HAzPop as well, which lets you browse through a regularly updated database of natural calamities worldwide, such as fires, storms and earthquakes. Also by putting together these data with the population database, you can find out the number of people affected, who could come to rescue and many more information. Along with this, there is Glenn Research Center: The Early Years, which is an iPad app that takes you on a tour of NASA from 1941 to 1979.
Don't worry if you are not as iOS user, NASA has something for the Android users too - the Space Weather app. Through this app, you can check up on the latest coronal mass ejections and magnetosphere changes.
And it doesn't end there. NASA has got something for your recreation purposes as well. There is a Unity-based Spacewalk game in which you can replicate various EVAs conducted by ISS astronauts. You can play it online, on Mac or on PC. FYI, EVA is a commonly used acronym for 'Extravehicular Activity', which describes any activity for which a crew member of a spacecraft must go outside the protected "shirtsleeve" environment of the orbiter's crew cabin.
Finally, NASA has a large collection of 3D models, images and textures that you could use for education or personal purposes. All of these for no charge at all.
You can get all the apps and programs in here.