--Credits section updated

--About the App section updated

--References added

--Updates to Approaches to Chest X-ray and CT Head

--Errata fixed in Cases 1, 2, 3, 4, 9, 10, 12, 13, 14, 15, 16, 27, 31, 37, 40, 44, 51, 52, 56, 58

--Cases 42, 63 updated with new content

--Errata fixed in MSK anatomy quiz (11 items)

--Errata fixed in Neuro anatomy quiz (2 items)

--Errata fixed in Abdo/Pelvis quiz (4 items)

--Errata fixed in Spine anatomy quiz (2 items)

--Errata fixed in Chest quiz (1 item)