Doesn't support custom fields

This looked like a strong contender and I was even considering the premium option – but it doesn’t even give the option to include a custom field so it’s a non-starter.

After some digging I found this info: https://fatcatapps.com/optincat/docs/add-more-fields/

In general, I find the “We didn’t provide this feature because we don’t think you should use it” to be condescending. Every situation is different and there are other business outcomes besides “more subscribers” to consider, so how about you let me decide what “best results” look like. I’ve decided a company with this philosophy probably isn’t going to have the right customer service for my needs in general so I am looking elsewhere for a solution.

Clearly lots of people are very happy with this plugin. But if you need an option with custom fields you can save yourself some time and skip this one.