Jeder is - as mentioned before - a pronoun that can be used adjectivally and substantivally (like keiner as well). Jeder is the word corresponding to every and each. Understandably there is no plural of jede, as there is no plural of every or each.

Jede Straße hat einen Namen. = Each / Every street has a name. Möge jeder sich um seinen eigenen Kram kümmern. = Everyone should take care of his own business.