Creating the best messaging app is a complicated problem to approach. Everybody's always looking for a unified way of keeping in touch with their friends and family, but with so many different services finding success on different platforms and in different regions of the world, there's just no way to rally wide enough support around a single product to truly solve messaging once and for all. Of course, that hasn't stopped Google from trying, and from Google Talk to Hangouts and RCS messaging, the company has seen a lot of success — and a lot of failures — throughout the years. Even some of Google's shuttered messaging platforms, like Allo, ended up paving the way for far more successful products.