This plugin brings faster autofocus to NINA and also has a nice "aberration inspector" to help dial in backfocus distance. 

Target Scheduler allows for completely automated imaging. You designate the targets and exposure plans, then TS picks the best target to image at any given time. It saves you from having to create time-consuming sequences every day. 

I use this plugin constantly. It creates a webpage on your local network that shows your images and important data, like star size, image mean, etc., which can help you determine how a session is going.

Ground Station allows you to receive messages from NINA during your session through email or other messaging apps. I use it to get updates on the progression of sequences during the night, including any failures. 

This brand-new plugin provides a quick and easy way to calculate how many exposures can fit into a session. 

Target Planner helps you determine if the moon is too close to an object to image on any given night. You can even create a chart for an entire year of imaging.