Google launched a brand new app devoted to Street View imagery. It also lets you add your own photosphere, which is something Google promised when they dropped the Views feature from the other program.
The app lets users either follow 360-degree imagery and/or contribute their own via their device's camera.
Here is a screen shot of how to explore Google Maps and user galleries in the Street View app:
Here is a screen shot of how to contribute your own photo spheres directly to Google Maps in the Street View app:
You can download the app on iOS or Android.
Forum discussion at Google Maps Help and Google+.