Free PROJECTS FOR SEO?

Hey, guys so I've been wondering if hosting free services and linking them to my main website would be a good way to gain new customers and SEO?

1. Should it be related in some way to my main project?
2. Has anyone tried this out with their saas?

I've anyone was wondering, I built a whole Twitter manager where I schedule tweets, generate new tweets using gpt3 and you can engage with people in lists easily (Basically tweethunter lol). I'll probably open source it as well if anyone is interested.