Which for WordPress Blogger
1) Yoast SEO
This plugin helps you to manage and set your post or page SEO such that you can easily search it on Google. It also allows you choose a focus keyword when you write articles and then ensures that you use that focus keyword everywhere. This is major advantage of it.
This plugin is very much useful in Email Marketing. The main function of MailChimp is to transform your visitors to readers by providing options to subscribe to your blog.
This is very effective and free plugin to convert visitors to your regular readers. It provides Web push notifications for your blog.
Jetpack assists you in keeping your WordPress site secure, enhance traffic, and engage with readers.
5) Contact Form
A must needed plugin in your blog because it develops a simple contact us form for your blog which readers can use to connect with you.