Packages with the appindicator use flag

app-misc / solaar : Linux Device Manager for Logitech Unifying Receivers and Paired Devices

gnome-extra / nm-applet : NetworkManager connection editor and applet

gnome-extra / synapse : A program launcher in the style of GNOME Do

mail-client / claws-mail : An email client (and news reader) based on GTK+

mate-base / mate-applets-meta : Meta package for MATE panel applets

mate-base / mate-control-center : The MATE Desktop configuration tool

mate-extra / mate-polkit : A MATE specific DBUS service that is used to bring up authentication dialogs

media-sound / guayadeque : Music management program designed for all music enthusiasts

media-sound / pithos : Pandora.com client for the GNOME desktop

media-sound / xnoise : A media player for Gtk+ with a slick GUI, great speed and lots of features

net-im / slack : Team collaboration tool

net-misc / remmina : A GTK+ RDP, SPICE, VNC and SSH client

net-p2p / transmission : A fast, easy, and free BitTorrent client

net-wireless / blueman : Simple and intuitive GTK+ Bluetooth Manager

www-client / uget : Download manager using gtk+ and libcurl

x11-misc / redshift : A screen color temperature adjusting software

x11-misc / screenkey : A screencast tool to display your keys inspired by Screenflick

app-misc