Pop Convert ‑ Pop Ups, Banners

I have tried around 5-7 email pop up apps so far very thoroughly and this one is the most easy to customize (just try all those awesome sliders they have) while for other apps everything needs to be done via CSS. The app is easy to use and navigate which is exactly what you need from an app like this. Their support is super responsive and helpful!

The only thing that is missing is a sidebar widget that will allow you activate the email pop up on demand (users tend to close the pop up when they visit a website but eventually they want to use it when they are ready to buy). They mentioned they will add this functionality soon. When they do no one will be able to beat this app!