According to their official announcement, Google Analytics feature App + Web Properties has entered open beta. You can now combine data from your website and your mobile app into one property.

It seems that GA’s move towards event-based tracking is slowly becoming a reality. Analysts, will have to switch to a new measurement schema as efficiently as possible and make sure the change doesn’t wreak havoc in clients’ current reports.
I see this change of the measurement schema as a step towards better data interpretation. The App + Web properties will have a different reporting structure utilising different data visualisation than what you are used to in GA now. Based on screenshots I have seen, those design changes are going to be beneficial. Finding meaning in piles of data will be a bit easier.
Krista Seiden wrote an extensive article about this update. I recommend reading it very attentively.
If you want to get into the weeds, check Google’s official documentation of this feature.
Update 2019/08/05
Simo Ahava has joined the conversation and published a tutorial on getting started with App + Web Properties. I also love his table highlighting differences between Universal Analytics and the new measurement model.