The Hangouts app is loved by some and hated by others, who prefer the good old fashioned Google Talk. Unfortunately, Hangouts has a few issues that are quite annoying, such as the lack of a return key when returning messages. But fear not because with a bit of patience and a willingness to learn and some new tools, you will be able to change Hangouts to be more usable.
To do this, you need APKtool and a guide written by XDA Recognized Contributor CNexus. To make the necessary modifications, you need to have the Hangouts application extracted from your device. Keep in mind that Hangouts is updated from time to time, so you would need to repeat the process after every update. After decompiling the application, you need to enter few Smali lines and compile it again. With a little dose of luck, your Hangouts application will show your onscreen keyboard’s enter key rather than the smiley key.
To learn more about the process, head over to the original guide thread.