A method for remote operation of a downhole tool positioned in a subterranean wellbore extending from the surface and through at least one hydrocarbon-bearing zone, the method comprising the steps of: maneuvering an untethered, first mobile device from the surface, in a downhole tubular extending through the wellbore, into proximity with a downhole tool positioned in the wellbore to be received by, and to contact, a first seat of the downhole tool, the seat having a profile of a size to allow the first mobile device to make contact with the first seat but not to pass through the downhole tool; transferring an electrical signal of digital data between the maneuvered first mobile device and the downhole tool; powering the downhole tool by means for powering the downhole tool and by the first mobile device being received by the first seat, wherein the first mobile device restricts fluid flow through a primary passageway of the downhole tool, wherein the fluid flow is altered to be forced through another passageway to create power for the downhole tool; removing the first mobile device from proximity with the downhole tool; maneuvering an untethered, second mobile device from the surface, downhole, into proximity with the downhole tool, to pass through the first seat, to be seated on, and to contact, a second seat of the downhole tool, the second seat having a smaller diameter than that of the first seat; transferring another electrical signal of digital data between the downhole tool and the second mobile device; removing the second mobile device from the downhole tool to the surface; and transferring data from the second mobile device at the surface by means for collecting data. maneuvering an untethered, first mobile device from the surface, in a downhole tubular extending through the wellbore, into proximity with a downhole tool positioned in the wellbore to be received by, and to contact, a first seat of the downhole tool, the seat having a profile of a size to allow the first mobile device to make contact with the first seat but not to pass through the downhole tool; transferring an electrical signal of digital data between the maneuvered first mobile device and the downhole tool; powering the downhole tool by means for powering the downhole tool and by the first mobile device being received by the first seat, wherein the first mobile device restricts fluid flow through a primary passageway of the downhole tool, wherein the fluid flow is altered to be forced through another passageway to create power for the downhole tool; removing the first mobile device from proximity with the downhole tool; maneuvering an untethered, second mobile device from the surface, downhole, into proximity with the downhole tool, to pass through the first seat, to be seated on, and to contact, a second seat of the downhole tool, the second seat having a smaller diameter than that of the first seat; transferring another electrical signal of digital data between the downhole tool and the second mobile device; removing the second mobile device from the downhole tool to the surface; and transferring data from the second mobile device at the surface by means for collecting data. <EOS>