More information about this error (version 1.6.1 of desktop everdo).
From section " 5.3.1. Noteworthy obsolete packages"
- The deprecated libappindicator libraries are no longer provided. As a result, the related packages
libappindicator1,libappindicator3-1andlibappindicator-devare no longer available. This is expected to cause dependency errors for third-party software that still depends on libappindicator to provide system tray and indicator support.
Debian is using libayatana-appindicator as the successor of libappindicator. For technical background see this announcement.