We had already some threads here, probably you could get many interesting informations in 1, 2, 3, 4, 5.
The link posted above by Mr.Lesse has GCam ports up to version 8.8 which run very well on my plussed FP3 and lead to really good pictures in most situations without any extraordinary configuration. But in many cases I just use FreeDCam from F-Droid.