I just went into System Information on my MBP and I see that the Kindle 1.12.4 update was installed on 7 October 2015 but no other updates were installed until today when it updated to 1.20.2. I'm not sure if that is Amazon being wonky on pushing out updates or Apple being wonky about notifying me they are available, perhaps both. No big deal on the Mac version of the Kindle app since I rarely use it. I cannot even remember the last time I did use it.