Hello Gpasser!
It's great to have you at the Apple Support Communities. I see you have an app that you'd like to share via Family Sharing and I'm happy to help you out.
Start here:
What types of content can I share with my family using purchase sharing?
Once you've verified that the app is sharable, let's try the steps here to walk you through downloading a shared app.
If you don't see your family's shared content
In particular these steps:
See if the purchase is hidden
If a family member has hidden one of their items, no one in their family can see it. Your family member can unhide those items if they want to.
Make sure your device meets the system requirements
To access your family's shared content, you need an iPhone, iPad, or iPod touch using iOS 8 or later, or a Mac using OS X Yosemite or later. If you're using an older device, you won’t see your family’s shared content. If you're using an Apple TV, you can see shared movies and TV shows only.
iOS 8 and OS X Yosemite are required to set up or join a Family Sharing group. See the system requirements for Family Sharing.
If you have further issues downloading a shared app, you may need to Contact Apple Support.
Take care.