Hi…I sorry to say, but you’re in the wrong forum.
It a different app as „djay“, but you can work with djay, too. It should also connect to your controller natively also via Bluetooth.
The app you are talking about has a paid version to give you access to iTunes & deezer only, and your files app!
Djay pro gives you access to the platforms tidal premium, SoundCloud go+, beatport beatsource link and the files app.
Djay app has also a monthly paid option which gives you some special benefits in case of your mixing experience.
My honest advice, try both in thee free version. I looked to the DJ player pro app imo it doesn’t look very nice for me.
You should also compare the App Store description of bothe apps very careful and watch some videos on YouTube about both iOS versions.
Djay is by far the most professional DJ app atm and I think you will agree if you see them side by side.
At the end it will be a matter of tast…decide after using both for some days😉
Wish you and your kids a great party Christmas