In October of 2014 a friend and past colleague of mine, Mustafa Ali, wrote a great Medium article to help solve a problem that many Android developers have encountered at one point in their career. The Dex method issue in short is a limit to the amount of executable methods allowed in Android's Dalvik Executable file (the one used to execute Android code). Shortly after writing his guide Google did the unthinkable... they released a support library. The library creates multiple dex files to help apps that are large get around the single dex file limit issue. Though this is a great solution for large apps Google suggests to use Proguard to strip your app of unused code or to reduce your dependency on libraries as a whole. The former is much easier than the latter.