Absolutely. Just head over to pro.joistapp.com on your laptop/desktop computer and sign in with your Joist account's email and password.
Everything you do with the Joist app on your computer will stay up to date with the Joist app on your smartphone/tablet, and vice versa. Just make sure you're signed into the Joist app with the same email address on all of your devices.
Many contractors will use Joist from their phone when out in the field, then switch to their computer when at home or in the office.
You don't need to download an app to use Joist on a computer. Just head over to pro.joistapp.com to get started today.