Thanks! Yes, I found that a huge percentage of visitors to the site were on mobile (especially for HN/reddit/etc traffic) and when your product is a desktop app there's not much you can do with that, so for a long time I effectively didn't have a call to action for most visitors at all, which isn't great for anybody.

Under the hood it's just a tiny automated email flow set up via Mailchimp that sends out the download link when you sign up. Nothing fancy, but it's easy and it does the job.