Yes, you can access your account from more than one device, using the same login information.   If you have customized your weekly plan (i.e., deleted recipes or added grocery items) on one device and then log in with a different device, the changes you made will be synced between devices.  

Should you have any questions about syncing you can contact Customer Success 
at 205-377-7701 or 800-372-4811 or