Helpful app for Anxiety & Panic Attacks: Rootd

I've been looking for an app that worked for me and was either free or affordable.

I found this app called Rootd and it has been really helpful for me in terms of getting through panic attacks. I also find reading through the content calming, and like the way it's illustrated. All of its basic features are free. I haven't paid but I feel like I'm getting what I need out of it.