Subscriber choice subscription plugin?

Hi

Is there a subscription plugin that allows the website visitor (subscriber) to choose when they receive an email of posts? I would like them to choose whether they receive either:
(a) an email each time a new post is created
or
(b) a daily newsletter listing links to all the new posts that day.

I have only managed to find plugins that allow ME to choose one option (not the subscriber) and apply that to all subscribers.

Can anyone point me in the right direction please?

Thank you