An unofficial guide to restore indicator functionality on elementary OS
The indicator stack on elementary OS consists of the indicator-application package and the corresponding wingpanel-indicator-ayatana wingpanel component.
The standard Ubuntu indicator-application package needs patching to enable support for Pantheon - you can download a premade patched .deb here or read the instructions below to patch it yourself.
The wingpanel-indicator-ayatana package is no longer included in the standard elementary repos, however you can download the latest .deb here and the source is still avaliable here.
To install the packages, you can use a .deb installer like Eddy or run sudo dpkg -i filename in your terminal.
Once you've installed both packages, a reboot should get your indicators working in Pantheon.
First, download the source to a directory of your choice by running bzr branch lp:indicator-application in your terminal (you'll need the bzr package installed if you don't already)
The patch itself is very small and straightforward - edit the indicator-application.desktop.in file located in the data folder and edit it so this line:
OnlyShowIn=Unity;GNOME;
becomes
OnlyShowIn=Unity;GNOME;Pantheon;
and save the file.
Now you can generate a patched .deb - the first step is to install the build dependencies by running:
sudo apt install debhelper dh-translations dh-autoreconf dbus-test-runner gnome-common xvfb libglib2.0-dev libgtk-3-dev libdbus-glib-1-dev libjson-glib-dev intltool libappindicator3-dev libindicator3-dev libdbusmenu-glib-dev libdbusmenu-gtk3-dev
in your terminal.
The final step is to run debuild -i -us -uc -b in the root of the indicator-application folder. Once this has finished, there should be a .deb for you to install in the parent directory.