ONEWITHFISH review for Mailmunch Forms for Mailchimp

Why does it seem every Shopify app is a bait-and-switch? Selected this one because it didn't seem shady, but 15 minutes into setup and I find out the only one I can use on the free plan is a silly popover. I'm willing to pay for the right product but not if I can't test it out first. Why can't apps be upfront about this instead of wasting everyone's time?