Hi there,
Thank you for the kind words, much appreciated!
With regards to being able to share the in app purchase functionality with other members of your family, I think Apple already allows this. I googled and found this:
https://support.apple.com/en-gb/HT201085After purchasing on 1 device, try going to another device that is part of the family of devices, run my app, then tap the Info icon, then tap Restore Purchases.
Let me know how you get on!
Regards
John