From the first moment you log in, Flora is simple to use. Here, you get to you grow "trees" in a virtual forest, but only so long as you don't interrupt their growth by using your phone. You can even ...

The Sapling app rewards users with credits for tasks completed, left. The credits are used to purchase trees used in reforestation projects. (Sapling Images) Two high schoolers who became friends ...

Lindsey Ellefson is Lifehacker’s Features Editor. She currently covers study and productivity hacks, as well as household and digital decluttering, and oversees the freelancers on the sex and ...