A full version of the software can be downloaded to computers.
Chromebook, iPad and Android devices use the app version which can be downloaded from the various webstores associated with each device. The app version has a smaller palette of programming blocks but typically contain all features students need to successfully program at the elementary/middle school level.
If you plan to use an iPad or Android device, please check the system requirements to ensure your device has the bluetooth components necessary to pair.
LEGO Education EV3 software and curriculum are free to download.
LEGO Education Curriculum Link (You'll need to scroll down the page to access each)
LEGO Mindstorms EV3 can be used with Swift Playground app available on iPads.
Scratch is a free software from MIT Media Lab that runs on both Chromebooks, Laptops and Computers. A group called Code and Circuit have developed an extension so you can program a LEGO EV3 robot using Scratch.
Link to Documentation on how to use the extension with LEGO EV3 Robots