Name: Ledger
Homepage: http://ledger-cli.org/ & https://github.com/ledger/ledger
Why should this be included in the repository? Ledger is a powerful, double-entry accounting system that is accessed from the UNIX command-line. I personally use it to handle the finances for my wife and I, and I think it is a tool that many *nix users would also enjoy on their desktop. Much like the password-store, it takes the approach of having information stored in basic text files, that will always be open and available to the user, and using a simple open source tools to manage it. Due to it being a CLI tool, it is also very script-able and flexible. It's just an overall great open source tool. Simple, but powerful.
Is it Open Source (yes/no): Yes (BSD)
How many users do you anticipate will use this software? I am not entirely sure how many users will use it on Solus, but I do think it is a tool people will appreciate. It has a growing following, and is supported on all of the major distributions.
Link to source tarball/zip file: https://github.com/ledger/ledger/archive/v3.1.1.tar.gz

Also, I have already done a build of it using solbuild, and created a patch submission request which can be found here:

https://dev.solus-project.com/T2803

Let me know if there is anything else I can do. Thanks