Is pro worth the money ?

Answer 1

No, not really.

Ads could just be blocked with any ad-blocker (i have not seen a single ad so far). The "real world practice" is basically exercises that are avaliable online for free anyway. And if u are gonna pay for basically syntax tutorial, u might as well just use any one of hundreds that are free.

It's a personal opinion though.

Answer 2

Further to Aleksei Radchenkov's answer, Pro enables a bit of extra practise in the form of A.I. tasks/quizzes and unlimited hearts.
If you'd like to support the app and the development team, it's probably worth it. If you're only looking from a user's perspective, it might not be.