Follow these steps used to de-compile the apk!
1. Obtain .apk file
2. Decompile .dex to .jar - Once the file is unzipped, one needs to decompile the classes.dex file. The dex file is the Dalvik executable file. The dex2jar tool is used to decode the .dex file to a .jar file as follows!
C:\softwares\dex2jar> dex2jar.bat classes.dex
3. View source code
Now, you need to open the decoded .jar file using a decompiler of your choice.
Thank you.