Earth day is on April 20th and celebrated by 173 countries around the world. You can learn all about it and use some great iPad apps to learn all about it including the history, news and much more about this important day. Plus, you can celebrate a healthy, happy earth all year long with many of the apps. Here are some of the best:

The Earth Day Guide app for your iPad is free and  this guide will teach you all about this worldwide yearly event.

The Google Earth iPad app is also free and you can use it to find any place on earth. The satellite imagery will let you feel as if you are right there.

The Living Earth – Clock & Weather app for your iPad is $2.99 and gives you a 3D view of earth from outer space. There are accurate cloud renderings that display in real time so you can see storms as they are happening from right on top of them. You can also watch sunrises and sunsets and seasons as they change. The world clock that comes along with this view has an alarm function and weather app with a four day forecast for more than 22,000 global locations.

The GoodGuide iPad app is free and allows you to scan products at stores to reveal whether they are safe, healthy or green for the climate, energy efficiency and animal welfare. You can choose the issues that you care about the most and see whether the product passes of fails for the specific criteria you set for it.

The Make Change, Not Waste app for your iPad rewards Whole Food Market shoppers by giving them coupons and badges for their green living choices such as using reusable bags, recycling and biking . When you complete ten green living choices, you get to unlock a coupon or donate a percentage of the coupon the Whole Planet Foundation.

The 50 Greatest Photographs of National Geographic iPad app is $4.99 and is filled with all the photography that has made National Geographic such an iconic media source. It also has a video introduction from the Editor and Chief of the magazine, bios of all the photographers, and lots of background information on the photos and videos. There are also interactive maps and timelines.

The Fotopedia Heritage app for your iPad is free and has more than 25,000 photographs from all over the world. You can browse through the collections, save them as favorites and use them as wallpaper or share to your social media networks.

The Earth Day Carol iPad app is free and is an interactive eBook that is similar to “A Christmas Carol” by Charles Dickens but has the ghosts of Plastic Past, Plastic Present, and Plastic Future talking about the importance of Reduce, reuse, and recycle to younger children.

The Al Gore – Our Choice: A Plan to Solve the Climate Crisis app for your iPad is $4.00 and 100% of the earnings will be donated to the nonprofit Alliance for Climate Protection. It includes Al Gore’s breakdown of global warming and what is being done to curtail it.

The Britannica Kids: Rainforests iPad app is $4.99 and is for elementary school children so they can learn all about the rain forest. It has games, interactive images and information about 21 different rainforest animals and talks about things such as what the rainforest are, the plants that grow there and what kind of threats the rainforest is under. It’s designed for children 8 to 12 years old.

The Art Authority for iPad app is one of the more expensive ones at $9.99, but it has all sorts of photos, facts and fossils. It features multiple artists and is like an art gallery of the planet. The high-def images are broken into historical periods for easier browsing.

The ARTREE for iPad app is $1.99 and allows you to create beautiful trees with your finger. This is a relaxation and art app that you can create wallpapers with.