Below are some Apps that I have used that I found really interesting. The reviews are my own opinions and are not sponsored by anyone. Currently iPad/iOS apps, Android apps will be updated soon.
Apps with an asterisk next to the name are also available for Android devices.
1. Bill Nye the Science Guy (free) -- Who doesn't want an app from everyone's favorite bow tie wearing science superhero? Celebrating the 20th (seriously?) anniversary of the show, the app features two games: one where you can learn about gravity and orbits as they launch a probe to Pluto, as well as another where you can explore the fossil record in Bill's backyard. In addition, there are several easy at-home science experiments that you can do, as well as clips from the show. It's a great app, and hopefully newer updates will add even more awesome content. Also, Bill Nye will teach you how to tie a bow tie!
2. NOVA Elements (free) -- NOVA has a great app where you can explore an interactive periodic table complete with pictures and information, as well as a model building kit, a game where you can explore the elements in compounds you find and use every day, as well as watch the NOVA episode "Hunting the Elements." It's a great resource for anyone looking to find out more information about the stuff that makes up everything!
3. BioInteractive EarthViewer* (free) -- This app was launched last year along with Howard Hughes Medical Institute's Short Film "The Day the Mesozoic Died." It goes through all of the geological periods of Earth's history complete with dates of major geological events, biological events, mass extinctions, as well as impact events (asteroids). Each of these events shows up on the timeline, along with a link to the location on Earth if applicable. In addition, as you scroll through the history of the Earth, you can watch the continents move, as well as monitor the length of the day (did you know that it has changed throughout Earth's history?), and the composition of the two major gasses in the atmosphere for life, oxygen and carbon dioxide. You also have the ability to explore certain topics in greater detail.
4. Star Walk HD ($2.99) -- This is by far the best astronomy app that I have found. It allows you to locate different objects in your current night sky utilizing your device's accelerometer. You can choose to have constellations show as just stars, line models, or corresponding shapes. You can also turn on satellites if you want to locate them. Clicking on objects such as stars, constellations, or sattelites will give you information about each object. It even has an option for night vision so checking your device will not affect your eyes. The Sky Live function gives you information about the Sun rise and set, Moon rise and set, as well as planet rises and sets. I think it is definitely worth the price.
5. COSMOS* (free) -- The companion app to the Neil Degrasse-Tyson miniseries, this app has great resources to maximize your learning. It gives you links to watch to complete episode using the FOX NOW app, as well as the Cosmic Calendar referenced in the show, and more detail about some of the topics discussed.
6. Seafood Watch* (free) -- Part of the Monterey Bay Aquarium's Seafood Watch program, this app lets you look up different types of seafood on your phone so that you can make more environmentally friendly choices. Did you know that not all farm raised fish is good for the environment? In addition to maintaining an up to date list of ocean-friendly seafood choices, it offers alternatives to fishes marked as *avoid.* It also allows you to locate local restaurants that serve sustainably caught seafood.