How to delete an app that keeps the phone from successfully booting up? I need to delete an app but I cannot access anything with out it restarting every 5 seconds (this is an infinite restarting process, so the device never fully powers up to become usable). How can that be achieved? Is it possible to do so from the recovery menu?
As I've pointed out in my comment on your question, this rather is an XY problem – your real issue is to delete that app.

That's what safe-mode is intended for. You can find a detailed tutorial at HowToGeek, describing how to enter safe-mode, and what steps to take from there. I'll try to sum it up in a short list here:


Usually you'll find an option to boot into safe-mode when invoking the power menu (long-press the Power button while the device is operating in "normal mode" – not an option for you, as your device is stuck already. Refer to our safe-mode tag-wiki for alternatives: usually it's long-pressing power to switch it on, and as soon as the logo appears press vol+ and vol- simultaneously. Hold them pressed until you see the text "Safe Mode" appearing in the lower-left corner of the screen
While in safe mode, none of the user-apps will be executed – they will be disabled. So your app should not be able to "intervene" here
System stuff is still fully operational, so go to Settings › Apps, scroll to your app, open its entry, and from that screen uninstall it


Problem solved – hopefully :)