Methods and apparatus of pressure activated completion tools for hydraulic fracturing and related processes are provided. In some embodiments, the hydraulic fracturing apparatuses for accessing a subterranean formations can include a tubular body to be fluidly connected in-line with a completion string, the tubular body having at least one burst port configured to receive burst inserts (burst plugs), and a movable inner sleeve that can slide along the inside of the tubular body when exposed to hydraulic pressure from a first position to a second position. The tubular body can also have flow-port(s) that are blocked when the movable inner sleeve is in the first position and opened when the movable inner sleeve slides to the second position.