It has a 1/8" headphone jack, which—in theory—is what’s missing from the iPad Pro/Air. In practice, TBD.
“simple”, “cheap”, and “good enough” are highly subjective, but there are options: TASCAM US-2x2HR ($149), PreSonus Studio 24c ($159), MOTU M2 2x2 ($179), PreSonus ioStation 24c ($270), Apollo Solo ($500), etc.