It's Earth Day, and what better way to celebrate the great outdoors than becoming a naturalist?
The app iNaturalist gives people across the globe a chance to document all the plants, animals, and fungi around them. It's great both for a great hike, or if you're not comfortable leaving the confines of your home, your backyard works just as well.
If STEM is more your bag, you can try the "100 Days Of Code" challenge. The rules are simple: Just practice code one hour a day for 100 days and you'll become a pro. Go to the #100DaysOfCode website for more information.