The HTC One M9 will be available for purchase in the coming weeks, but if you just can't wait there are ways to get a taste of the new device now on your current device. The official M9 camera has been extracted and ported for use on other Android devices. The only requirement here is that you are running an AOSP Rom or a Rom that is based on CyanogenMod.
This is especially exciting for anyone using the Google Play Edition of the M8 since you can run the latest Sense camera on your device even though your software is actually AOSP. The Camera app includes Selfie, and Panorama modes as well as Bokeh and Split capture modes. There are many other new features included in this app. Installation is easy, but does require that you are rooted and have a custom recovery installed. Simply boot into recovery mode and flash the two necessary zip files and you are done. Grab the files needed from the link below.
via DroidViews