Google phots is a very good application where you can save and backup photos and videos on your phone to the this app.
It gives 15GB of free storage.
You can choose auto backup option if you want to backup all photos on your phone.
You can even select the number of folders you want to automatically backup.
And you can also choose while of wifi/data mode to backup your data.
Another best thing about this application is, it makes the beautified pic of an existing picture on its own and it collect a series of photographs and make an album automatically and similar it makes videos, animations etc.
This application is almost Inbuild in all smartphones.
It is a great application.