There are some differents- I divide one large plugin into 3 parts.
a. rex_firebase_authentication supports not only facebook email, but also google and twitter, Anonymous.
b. more query features in rex_firebase_query. Some features are newest which released at Nov 4, 2014 (Version 2.0.0 of firebase api).
c. add "transaction" feature in rex_firebase. Merge types of "set value"/"receive value" (string, number) into an action. Add some extra expressions.
In my experience, programming with firebase is not simple/easy for normal C2 users which do not have programming background. So I would like to encapsulate some logic with firebase into new plugins.