John the Ripper is a well-known free-open source password cracking tools for Linux, Unix, and Mac OS X. A Windows version is also available. You can also use John the Ripper as an Android hacking apps by installing it into the Termux Android.
John the Ripper offers password cracking for a variety of different password types. It goes beyond OS passwords to include common web apps (like WordPress), compressed archives, document files (Microsoft Office files, PDFs, and so on), and more.
A pro version of the tool is also available, which offers better features and native packages for target operating systems. You can also download Openwall GNU/*/Linux that comes with John the Ripper.