ShiftedFrequency

It's purpose built. It's not trying to be everything to everybody. If a customer's charge doesn't go through - send them messages. If their card is going to expire - send them messages. If they pay for something, send them a receipt. If a charge is coming up, send them a message. The long and the short of it is that it comes down to results. We used to spend many hours every month chasing down customers with failed charges - and we were never pre-emptive with expiring cards. We now spend very little time chasing customers on billing. And their bills get paid. Period. We also like the Zapier integration and the ability to cc us on messages.

It allows you to automatically chase people for payments and you can set up quite custom emails. It also offers to send receipts which you can embed online with an easy to use billing update page included as well :)