Google had really great products, that almost everyone I knew used, then they scrapped them for new shiny thing that competed. The one that angers me most is Google Talk, it used to work with any XMPP client, until it did not, and now its long since dead. They made their own version of tinychat (hangouts) and then mostly killed that too.
Obligatory overview of things Google has killed, because its easy to forget some of the gems: