Question:

I'm looking for an open-source invoicing platform that allows me to use Stripe to auto-bill a client each month. <a href="http://theanchorapp.com/" rel="nofollow">Anchor</a> looks good but it does not provide subscription based payments. Is there a free app that can do this?

Take a look at:

<ul><li><a href="http://www.jbilling.com/" rel="nofollow">JBilling</a> (AGPL v3). I don't know if it supports Stripe but you can add your own integration by writing a custom plugin</li> <li><a href="http://killbill.io/subscription-billing/" rel="nofollow">Kill Bill</a> (Apache License v2), which has already a Stripe plugin</li> </ul>