Google Has been working hard to offer so many more tools to both publishers and developers. Here is a screenshot of the chrome web store, that has numerous apps that you can add to enhance your Google browsing experience. Naturally there are third party apps that you can explore and spend a ton of time looking for a bunch of your favorite new apps. Most of them are free although there are some that are not.
Most of the big companies have added apps, so make sure to check through the entire list.