Hey peeps! -- Saas Subscription Question

Lots of Saas Apps. Also a bunch of apps to track/manage subscriptions of different things. (I would assume some would track/manage Saas apps as well.) But I haven't checked.

Has anyone used one of these subscription management apps for dealing with Saas Apps?

If you have any insight, can you share how they work, what they do, do you like -- pro/con?

thanks