I have been using Ulaa as my default browser and it's been great. Particularly, Kids Mode has been very useful to restrict usage for kids.

I noticed for restricting sites for Kids Mode, you have provided option to block sites. While utilising this feature, I am forced to add multiple site urls in the block list which is not feasible and annoying.

You should provide an option that allows users to block all sites in Kids Mode and provide an option to add exceptions that will be very helpful.