Quicktime is usually good with everything including phone video files, I guess Realplayer is starting to go downhill since nobody uses it anymore. There is probably some codec/plugin to make it play .3gp files properly but not much of a point haha.
It sure does some very smooth video.
Here is a video I took of some black powder ignition during a recent photoshoot. It seems that it failed to autofocus properly before starting to record however.