Add Contact Individually to List

While building lists, I've noticed a feature missing that would be incredibly useful to our sales and marketing team.

There is NO FEATURE to add a contact individually to any static or active list! Using filters may not always be reliable, and sometimes I just don't know what I am filtering for because I just have their name and email. Creating a filter just for one contact is not convenient. It would be much easier and faster if we could just add contacts individually.

On top of that, there is no way to add a contact to an active list. This is a major issue! As active lists are continuously growing, it would be incredibly helpful to have an option to add contacts to active lists manually.