poglaa

The plugin enables user to add buttons with advanced settings in Gutenberg editor. This button is similar to default Gutenberg button but it has many extra settings.
It is possible to add fancy hover animations such as grow, shrink, wobble, float… There are also settings for hover background, hover background transition, border radius, button size.
It is possible to add custom styles for button or button’s hover state. It is also possible to set the button to open in new tab.

Advanced Button Block

Seems this plugin does absolutely nothing. With Gutenberg enabled, this plugin should added an advanced button option. However, it does not.

Does nothing

Lets you add a fully customizable button block in Gutenberg editor.

splitwit

This plugin automatically adds the SplitWit code snippet to your WordPress site. SplitWit lets you create a variation of your web page using our visual editor. It splits traffic between the original version and your variation. You can track key metrics, and let SplitWit determine a winner. No code needed.
After creating a SplitWit account, and starting a project, you can add the project ID code to the plugin’s settings page. That’s all you need to start improving your site’s conversion rate.
This plugin relies on SplitWit, a third-party service. The SplitWit service adds code to your website to run A/B experiments. It also collects data about how users interact with your site, based on the metrics you configure.
SplitWit Terms of Service: https://www.splitwit.com/terms-of-service 
SplitWit Privacy Policy: https://www.splitwit.com/privacy-policy

SplitWit

Optimize your website for maximum convertibility. This plugin lets you use SplitWit to run experiments on your WordPress website.

Advanced Button Block vs SplitWit