How does a flex pool work?

As a client, you can add flex workers to your flex pool yourself.

The flex worker must have worked for you at least once! This so that you can see whether the flex worker is competent and reliable enough. Is this the case? Top! Then add it to your flex pool. 💪
  

We used to add flex workers to a flex pool. However, this is since the new update; open sign up changed.