I just went to the Substack website, and it seems I need an iPhone to use it (I don't have that, and never will), plus I can't see if there is any free starting level, just that for 800 subscribers you need to pay $7 per month.

I use LeadsLeap as my Autoresponder for my own list (Upgraded with unlimited Subscribers for $19 per month, but you can start for free), and also Listnerds to get more visitors to my blog and my Lead Capture Pages, Listnerds is a Mailer and not an Autoresponder.

!ALIVE