How can I share Android apps with other family members?



I'm curious how could a family share apps, or if it is possible. I did some googling, and found snippets of advice here and there, though some of it is outdated.

In particular, I'm interested in sharing kid's games. I don't find it makes sense to have to buy a game on all the devices of a husband, wife, and grandparents just to have the game available to play when the husband is GPSing his phone, wife is typing an email, etc. I mean, do you buy a PS4 for all 3 children and buy 3 copies of GTA5 for a single family?

But at the same time, personal phone data can't be shared (such as emails), so is there a solution?

I've pondered a solution of creating a master account that can be shared with the family, and each device can add that account. Will such an idea be viable on Android 4.4?