The best way is to integrate with ZEBEDEE, of course! I've quickly checked out your games and I think BTC integration would be a great fit! Especially the horse racing ones, where you could do stuff like buy and sell horses for sats.

Please note though that BTC payments for in-app purchases are a bit tricky - the app stores won't like it, especially Apple. You can do it, but not as simply as "traditional" IAP. At the moment, Apple will only allow third party payments for IAP (which includes BTC) through a separate web view. This means your game would have to launch a web page where the player completes the purchase, then returns to the game. A bit of a hassle, which is why BTC is currently mostly used for in-game mechanics like rewards or P2P interactions, not IAP in the traditional sense.

If you're interested in integrating ZEBEDEE, the best way to get access and some support is to join our Discord, where we have a channel for game devs - #Game-dev. Tag @Jene and @MathG there and tell them Jure sent you to get some preferential treatment :)