If you are using iOS 8.4 on your iPhone, iPad or iPod touch, here are some things you can do that you may have not known.
1. To automatically store and back up all of your photos to the iCloud Photo Library, go to Settings, select Photos & Camera and then toggle the iCloud Photo Library option to the green "on" position.
2. You don't own an Apple Watch, but its app is now on your iPhone and it's undeletable. To get it out of sight, place it in a folder with other unwanted, undeletable Apple apps (press the app until it starts to wiggle and drag it on top of another unwanted app; a folder will be created) and drag the folder to the last page of your display.
3. To see which apps are draining your battery the most, go to Settings, then General, then Usage. Select Battery Usage and a list will appear in descending order of app battery usage for the last 24 hours or last seven days.