sioyek

Open source PDF viewer. Can do things like show equations, figures and citations at point by right clicking on them without going to their actual location.

With the extra functions available here, one can do things like export annotations and highlights to the actual PDF via the embed_annotations command, or more importantly, download papers at point

Local configs are at ~/.config/.local/share/Sioyek.

To fix any Qt problems, see here.

See also the available extensions.

Only change keys_user.config and prefs_user.config, both keys.config and prefs.config are for reference. Running sioyek from the terminal shows where the application searches for configuration files.