Pressure activated counting/indexing mechanisms for hydraulic fracturing sleeves and related processes are provided. The hydraulic fracturing apparatuses can include a tubular body having a housing and a flow port, a movable inner sleeve within the tubular body slidable from a first position blocking the flow port and a second position exposing the flow port; an inner indexing mechanism capable of being moved through a plurality of positions and can include the inner sleeve having a counting track comprising a plurality of different grooves; and a counting mechanism that can include a circular ring and pin that can be axially and rotationally movable in the counting track; an actuating mechanism can rely on the auto-jay counting mechanism to provide a mechanical signal to either allow an actuating member to pass through and not open the flow ports or be retained so pressure shifts the sleeve to open the flow ports.