Does anyone have a list or know some 3rd party applications like Calendly, where we can send leads and individual link (i.e. a token etc) to book a meeting? Calendly does not integrate into Marketo, but we are looking for ones that do that serve a similar function.
I wouldn't turn away from Calendly so quickly. It's quite easy, using Calendly's generic webhook API, to integrate with Marketo. You need a (very lightweight) intermediate gateway layer. We built one that updates the Marketo Program Status ("Booked Calendly Meeting" and even "Booked but Cancelled" because we like to be precise!) based on the Program that sent out an email.