You have a lot of options for WordPress popup plugins, most of them offer similar features like different popup designs, exit intent, page targeting, etc.
Here are some of my favorites:
Conversion works great. It has a ton of features, though it can be a bit complex to setup. It is a software as a service, not specifically a plugin.
Price: Free - $99/yr
Holler Box is a lightweight WordPress popup plugin with a feature-packed free version. It’s less complex than other solutions, and has a couple unique features like a chat box email capture and FOMO sales notifications.
Price: Free - $199+
Popup Maker is one of the most popular free popup plugins on the Blog Tool, Publishing Platform, and CMS repository. To get features like exit intent, they offer paid extensions.
Price: $89/yr - $249
Elegant Themes makes this popup plugin, which boasts a beautiful admin design. They do not offer a free version, but purchase gets you access to their other products as well.
There are a lot of other ones as well, but hopefully this list helps.