Google photos has recently rolling out its new feature, you can now manually back up specific photos.
With the help of this new feature you can take your photos Back up anytime any where you want. You can save what you want, when you want with manual backup.
It is very useful feature specially for those who don’t have wifi.
You have to Simply select photos, tap the three dot menu, then choose “Back up now”
This update (v1.18) is rolling out now in the Play Store: goo.gl/55OnIr