Although Chrome allows multiple profiles and offers an Incognito mode, sometimes you want to use different accounts with a web service. Google handles multiple logins pretty well, but there are other sites that do not. Sessionbox allows you to have multiple tabs open to the same site, each tab being it’s own separate entity.
A good use case would be Twitter. You may have a teacher account with Twitter along with a classroom account. With Sessionbox, you can open a tab for each account, and be logged into different accounts without messing with profiles or Incognito mode.
Another use is with a learning management system. One tab can be connected as the teacher while the other is logged in as a student. In this set up, you can see what the student sees while you make changes.