AvatarSync provides capabilities to synchronize profile pictures from various sources, like WhatsApp or Facebook. The functionalities used require a jailbroken iOS device (7.0-8.2) and a compiled version can be found on TheBigBoss-repository.
For implementing further matching modes two options are possible:
One can add further matching capabilities by implementing MatchingDelegate.h. The implementing class needs to be added to the MultipleBaseTableViewController.m in its viewDidLoad-method
For adding a singlematcher there are multiple custom ways to do this. See ImageApplyOptions.m#156 for examples.