Samsung Galaxy Camera GC-100 is now discontinued and so is the support and firmware updates. But you can put a fresh new life into it by flashing custom ROM on it. For this you will require GC-100 custom recovery. This will allow you to flash custom firmwares and all sorts of tweaks available online that will make the experience better.
This brings custom recovery to the Galaxy Camera, which is accessible by holding the zoom toggle to the right (red indicator should be on +) and pressing the power button. The difference between recovery and download mode is whether or not the shutter button is also held. Keeping the shutter button pressed will result in launching the Odin download mode.