We already know for months different initiatives from Google so you can share your shopping with your family, as the family plan for Google Play Música or newer family plan for Google Play applications. We now have more information of this library ‘ ia family via Google Developer documentation.
The family library is a method by which a family can share payment applications from up to 6 members, buying a single copy and in a few reasonable limits Google will use to prevent abuse of the system.
In the new information we are given a date, the July 2, from which all payment applications will be compatible with the familiar library, because it is the day in which enters into force the new agreement with developers with several points on family plan.
Specifically, this is what the section on family licenses of the agreement which will enter into force in a few months:
[…] The user can include, among others, a family group with administrator and family members whose accounts are linked with the purpose of creating such a group. Google Play in family groups are subject to reasonable limits to prevent the inappropriate use of functions to share with the family. Users who belong to a family group can buy a single copy of the product and share it with other members of his family (except for subscriptions and products in the application, which cannot be shared).
If the developer enable Developer Console option so users can share products previously purchased, this authorization will be subject to this agreement. If the developer wishes, you can include a license agreement user end (EULA) in your product so that it governs the rights of its users. However, if there is a conflict with the EULA, this Agreement shall replace it.
For purchases previous to this date, depends on developers If you want to enable compatibility with the family library or not. It makes sense will be thinking that it is likely that many of them don’t want it do (nobody likes suddenly offer your free payment application to anyone, whether family or not), but remains to be seen who are encouraged and who does not.