There's no one rate for the entire EU and you charge the rate based on where the customer is. Not sure this bloke really knows what he's doing.
That ended up being my conclusion.
Useful link. Thanks.
To me, the link says the bloke is doing it right. It says;
If your business stays below €10,000 in cross-border sales of digital goods per year, throughout the EU, then you can charge the VAT rate of your home country on all those cross-border sales. Once you pass the €10,000 annual sales threshold, you must charge the VAT rate of your customer’s country. For non-European businesses, simple rules apply. In B2B you should reverse-charge VAT. In B2C transactions, always charge the VAT of the customer’s country.

As @peteblue said earlier, he's charging 24% so he must be in Finland or Greece.
He wont have sold over 10k yet so he's charging the rate of his home country. After 10k he'll charge EU citizens the rate of their own country.