This directory contains a series of Android Studio screenshots of
creating an APK and then disassembling its functions into DEX
bytecodes, per function. This is done using the "Analyze APK"
functionality.

This functionality can show you the bytecode without having to resort
on command-line tools. However, you will not be able to patch and
rebuild an APK this way. For that you will need apktool and its
editable-and-recompilable assembly representation of the bytecodes
(called "Smali").

Note that constants that you address by their class and symbolic
names, such as Context.SENSOR_SERVICE and Sensor.TYPE_GRAVITY.
However, in the bytecode these constants are replaced with their
actual values, such as "sensor" and "9", which first appear on
screenshot 8.

Screenshots 9--13 show this: I am chasing down the definitions of
these constants by using "Command+O" and searching for the source code
of Context and Senor classes. The full source is not available
for SDK 26 yet, but Android Studio shows me the constant definitions
decompiled from the class files packaged with the SDK (and these 
have symbolic names, unlike DEX).