To switch down the device when the power-off button doesn't work properly, just long-press simultaneously both the power-off and volume-down buttons. Worked for me on Lumia 720, so hopefully will work for you too. That seems to be a higher-level power off. Try twice if it doesn't work at first attempt. Hope this helps.
@riiidaa: Have you failed to notice that the phone automatically turns on when plugged into power?
There are apps that will reboot, but if you want to save battery by turning the phone off (with the caveat that yeah, you won't be able to turn it on again until you get to a power cable, which does sort of limit the usefulness) it's *probably* possible for an app to do this, actually. It doesn't require any terribly special permissions on Windows, at least normally. On the phone there is an ID_CAP_BUILTIN_SHUTDOWN which says it lets you "Shutdown or reboot the system" though, so maybe it's only possible for capability-unlocked phones.
Do not private message me with questions that should have been posted on the forum! Not only are you wasting your time - I'm not going to bother writing an answer to such a question for only one person - but I will probably block you from PMing me in the future as well.
Some older devices still remain very popular. Phones like theHTC Desire, Sony Ericsson … more
23 Sep 2014
By Tomek Kondrat
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?