I looked up a bunch of similar products about 5 years ago. Just last month, I looked them up again, and found that many don't exist anymore.
It's definitely a tough market. I suspect that it will be the larger corporations with enough revenue that can release such products into the market - and probably even release them as free features of an existing suite of products (e.g. iOS with Downtime, Disney's Circle[1], etc), as opposed to a standalone product.