In order to make personal optimization possible, every user needs their own WordDive-account. If more than one person uses the same account, the app can’t separate the different users from one another, and therefore it’s also impossible to adapt the learning personally.
If the user is a child, he/she doesn’t necessarily need a personal e-mail account to practice with WordDive. A child can also use a parent’s e-mail address, if the parent hasn’t already registered with it to WordDive. If both the child and parent want to practice with WordDive, they need their own e-mail accounts to register as a WordDive-user.