Its asking me to signup repeatedly even though I have an existing free account. Even after signip with an existing account it asking me to create a new account and not allowing me to use it. This happens only in the private mode, so I am guessing they aren't able to get the browsing data to sell that's the reason why they are discouraging its use on private windows. Worthless!! Keep away and don't use it.

The support instead of acknowledging the issue asks to contact their support, they are aware of this issue. I will report this addon for abuse and privacy concern.