While I like the UI and ability to use filters to get the desired list, a 25% bounce back rate makes it more work than I can handle. For a list of 1,000 emails, I received over 250 bounced back. Since my email service only allows 100 sent at a time, I spent most of my day correcting the list (in case the balance has value for future use.)
I see potential and will continue to use since I invested in the product.
I hope the builders continue to improve the app and are successful.