pass-winmenu is an Open Source password manager similar to Pass for Linux, designed to be easy to extend and extremely customizable.
pass-winmenu is capable of storing passwords as GPG-encrypted files. They are organized into a directory structure intended to provide the advantage of simplicity and modularity.
Open Source GPG handles the cryptography; it is a high-quality, trusted security suite used by many professionals, Linux distributions and many others. Open standards make it easy to develop compatible multi-platform password managers (Linux, Android, Windows, Mac OS, etc.) Since the passwords are simply stored as encrypted files in directories, you have the option to organize them via your file manager. You can also synchronize them across your devices.
The passwords stored in pass-winmenu are encrypted with your GPG key. It can only be unlocked with the master password. This makes any potential attacker's job difficult as they will need to have your encrypted passwords, GPG keys, and your master password.
If you are looking for a flexible, customizable password manager provided modularly for integration into many different systems, then pass-winmenu will fit the bill.
There is an extensive but of information included at the author's site to get you started.