One of the main advantages of having an HTC One M9 is its powerful main camera. It has a sapphire camera cover lens that makes it scratch resistant and able to take vivid and clear images. Aside from that, the user interface on the camera is straightforward, and even new owners can easily navigate their way around the features and options. Even better, there are still hidden tricks that can make the One M9 stand out even more. 

Users can have the freedom of adding new modes to the camera app. With the phone oriented in an upright or portrait position, users can tap the four-dot icon in the lower left corner of the screen and then tap on the "Add +" option. This will open up a list of available modes and a brief description of each. Adding modes will have each feature added to the shortcut menu for camera modes, with the Bokeh, Panorama, Photo Booth, and Split Capture default modes already added. 

Users can also use the physical volume buttons of the One M9 as shutter keys. By default, one of the volume buttons will have no special function assigned to it, and users who always use the camera app can customize the option to have the buttons control zoom or act as the camera's shutter. On the lower left hand corner of the screen, users can tap the three dots and then touch the gear icon to go to the General Settings tab. They can then tap the Volume button options and assign the new functions.

The One M9 also has an app that would greatly help bloggers and artists. The built-in app, called the Print Studio, turns the snapshots into printed cards with different layouts and designs. In viewing an image, users just need to tap the Print Studio icon on the options at the bottom of the page.