It's a Microsoft product, free to download. You can use it free. And if you're on the free version, I believe you can post your reports to the public repository. If you want to keep it private then you'll need to get onto one of the pricing plans. A pro plan is $10/mo so not terrible for someone who will make good use of it.
I'm using it in my work right now. Looking at data in ways that were too labor intensive to set up and constantly update in something like Excel.
One great feature is the ability to use online dashboards which can be viewable through your mobile app as well. Not sure if this is part of the free or pro plan but we're making use of this daily at work.