The dex2jar project provides tools to work with Android .dex and Java .class files. It includes dex-reader/writer for reading and writing Dalvik Executable (.dex) files, d2j-dex2jar for converting .dex files to .class files, and smali/baksmali for disassembling dex to smali files and assembling dex from smali files. Additionally, it offers other tools like d2j-decrypt-string for decrypting strings. To use, simply run the provided scripts after unzipping the distribution file. For support, refer to the issue trackers on GitHub, SourceForge, or Bitbucket.