Project for Web Accelerator is a Power App I have used and was mentioned during this webinar. Ironically, when I just searched it up, a video showed up with the webinar's moderator. https://learn.microsoft.com/en-us/project-for-the-web/deploy-project-for-web-accelerator-power-bi-template

I wish Microsoft chose to pursue this Power App instead of trying to add more enhancements to the new Planner.  They are way behind other modern PM tools and I don't think they will catch up.  Another option could have been enhancing Azure DevOps for a waterfall/hybrid project approach, but doubt that's going to happen.