The exit-intent popup is powerful with a LOT of options. You can stick to the defaults and still have a good popup running in just a few minutes.

Popup maker is one of the best popup plugins I've used. It's very easy to configure and has a clean interface. It doesn't overwhelm with unnecessary options. Triggers and cookie control is very helpful. And there are a lot of targeting options which allow you to target your selected audience very specifically. Like other plugin makers, the developers didn't make the free one unworthy. Another cool feature of this plugin is the built-in analytics. You don't need to use another tracking tools to track the performance.