Well, Flyspray yet has no real plugin system and will not get some in short future. (2022-2023 at least)
So stuff here are just files that can be added to a Flyspray installation if you want to have such additional features.
These are complete experimental and may be dumped if useless or replaced by better solutions or are finally integrated into Flyspray main source.
They are meant to work with latest Flyspray release (https://github.com/Flyspray/flyspray/releases) and/or git master branch. They may just work with older releases by luck.
- gantt - Gantt Chart of a project, view gets complex quite fast, ok if there aren't too many tasks in a project. (view exists, still not very useful)
- kanban - Kanban View of tasks, tasks are grouped by their status (view exists, no interaction yet)
- team - Alternative dashboard of team members (stub, started)
- stats - statistics for Flyspray projects (stub, started)
- scm-git integration with Git repositories (stub, not started)
- scm-hg integration of Mercurial repositories (stub, not started)
- scm-svn integration of SVN repositories (stub, not started)