has many new features to discover. Here are some hidden tips, tricks and features inside the new OS.
Change video recording resolution: Go to Settings > Photos & Camera > Record Video and select from the options 720p HD at 30fps, 1080p HD at 30 or 60fps. Similar options appear for Slo-mo video, including 720p at 120fps or 240fps.
Pinch to zoom during video playback: This one's self-explanatory. Pinch to zoom in or out of a video when it's playing.
Back button: When following links or checking notifications between different apps, iOS 9 allows you to navigate back to the previous screen without bringing up the multitasking menu. Simply look for the "Back to previous app" option in the top left of the screen.
Select multiple photos and videos: Open any album, then look for the Select button at the top right. Tap this, then simply tap, hold and drag across to select all your chosen images.
Go back to album view: When viewing an image, swipe down to dismiss. This quickly takes you back to the album view instead of having to tap the back arrow in the top left corner.
Quickly navigate through photos: Slide your finger across the thumbnail slider at the bottom of a single photo view to scrub through a series of images.
Hide multiple images: Select a series of images, then tap Share > Hide.
Draw on email attachments: When you receive an image attachment in Mail, you can now draw and add annotations without leaving the app. Just tap and hold on the image to bring up the contextual menu, find Markup and Reply then you can draw on the image or even add text and a signature. Tap Done to insert it automatically in an email reply.
Recommendations: Swipe left from the home screen and see a list of location-based recommendations. These include restaurants, shops, bars and gas stations that are nearby.
Travel times to your next meeting: The Calendar app can now tell you when to leave for your next appointment. When creating a new entry, scroll to Travel Time and switch the toggle on.
Quickly send a photo or video: Press and hold on the camera icon to bring up a recording interface. Take a photo or video and it will insert it into your message, but not send it automatically like earlier versions of iOS.
Click here for CNET's complete How To guide on iOS 9.