Add a field for a self-assigned code

[CristianCantoro]

To avoid the constraint of always using the same device and browser you could add a field where the user is asked to provide a self-assigned (short) code that can identify her uniquely. In this way, the user can track her own data. This is a technique that is used in studies in psychology.

You can provide guidelines on how to generate the code, if you want (e. g. use the first letter of your name, the day of your birth, etc.), you may also have to check for collisions.

[CristianCantoro]

Note that this would also solve the issue of reporting for multiple people (e. g. relatives) from the same device.