As per the recent update by Google, when Family Library becomes available to users, up to 6 members from the family will be able to share purchased apps on Google Play. So if you have purchased apps post July 2nd (when the Developer Distribution Agreement update takes effect), you will be eligible for Family Library. Interestingly, you apps doesn’t need to be part of Designed for Families to be included in Family Library.
To opt-in previous purchases:
- Sign in to your Google Play Developer Console.
- Select an app.
- Select Pricing & Distribution.
- In the “Family Library” section, select the checkbox. Users will see whether previous purchases of your app are eligible for Family Library on your store listing page