Only allows you to use two types of emails. Gmail and Outlook, it doesn't matter what you used to sign up. It doesn't care what email you have. The only account it supports it Amazon. For all the above you have to link your accounts so they have access 24/7. The tracker is just a side feature of the app as well. It's mainly a shopping app full of ads. In summary, not only does the app not make sense, needing to have specific emails or accounts without specifying at sign up. Its also full of ads.