Eventually it is probably useful to split gpsapp into a backend that continuously monitor the serial port (similar to gpsd) and separate frontends that run only on demand.

This makes me think.

What if Hijack exposed a new device in /proc somewhere that was just another hook into the serial port. But it did so in such a way as to always allow multiple applications to connect to it simultaneously without locking it? Then multiple apps could use the serial port without worrying. It could be named something special like "freeserial".

Or does it already do this and I just don't understand how it works?