One of the developers here. We built Circles due to the same problem I encountered in previous projects after releasing the apps: how do you automate outbound communications with your users for the lifecycle of the product?

This initial version automates NPS tracking for post purchases/subscriptions (i.e. active users) for Stripe with individual and bulk replies. We plan to cover additional lifecycle stages (e.g. trial user, prospective user, etc.) with pre-built surveys like this one.

There is a free version so please try it and give me the good, bad and ugly