My team and I developed a nice tool, Open Drone Monitoring, if you're using multiple drones or flying them with your friends.
It's basically a QT (C++) server that will receive and compute multiple drones data in real time.
For now we only developed 2 applications : A json output stream used to feed a node.js server to display a map with all the drones connected, and a "blackbox" of the position data sent to the server in a sql database.
To communicate with the server we developed a plugin for Mission Planer, that will automatically connect and send your drone position every second.
If you do not use Mission Planer, you can still use the ODM Server but you will need to send yourself the Json containing the data (id/name, alt, long, lat, time-stamp).
To download the Mission Planner plugin :
To add it to mission planner simply unzip the file and put all the file inside in the Plugins folder in Mission Planner (as exemple : C:\Program Files (x86)\Mission Planner\plugins)
The git of the plugin : https://github.com/Nereidregulus/TcpStreamPlugin/wiki
If you think of any other application feel free to share, we already have few ideas but still looking for new ones :). And FYI The server has been built to make you add your own application, feel free to develop & share !