I am using a Raspberry Pi as the main controller for a project that will be constantly filming a video. My goal is for the Pi to stream the footage in real time to an Android device (using an app that I will develop myself). However, this camera will nearly always be used in a location where Wi-Fi access is not available. Ruling out the possibility of a standard Internet connection, what are the best ways to stream this footage to the device in real time without spending a lot of extra money?
You are using and android phone. So create a wifi hotspot on the phone, then connect the raspberry you phone's hotspot. Or you can create a hotspot on the raspberry pi itself. Try out this link Turn a RaspBerryPi 3 into a WiFi router-hotspot
It should be possilbe to send video over radio or bluetooth if for some reason you don't want to use wifi for some reason. Also do you mean no Internet access or not using Wi-Fi because those two are very different.