Matt Mazzeo, writing on Medium:

We have places review what we’re eating, good and bad. Places to review where we’re vacationing, good and bad. Places to discuss what we’re watching, good and bad. But where do we share the things we love? I dare anyone to review their 10 year history of “likes” on Facebook and tell me that it’s a good representation of the things they love. And yet, the world needs a home where people can share and discover the things that inspire us — that are too good to keep to ourselves, without making it feel like work. REX is that place.

The user interface reminds me of Instagram and the functionality reminds me of Pinterest — I expect Rex will find a sizable, dedicated user base.