Hello Maria,
Our application can be used on iPad and laptop devices.
To use it on an iPad, download the EF Class app app on the App Store (not EF Classroom).
On a laptop, open your Google Chrome browser, go to class.ef.com and click on Sign In.
EF Class is not currently available on phones and android devices.
I hope this helps and let me know if you need anything else!
Kind regards,
Nicolas
The EF Class Team