in that case, when you download the newer versions, you should after it downloads, try to access it. Once you do that it should take a minute to process, as it will say "staging app" or something like that, before giving you the option to update thethar, It will ask you to update the app if you have it installed on your phone. Then, abracadabra you're CK app should be updated if you did it right.
Unless stated otherwise by Arcaedian, your save files should all transfer over no problems. I have done an update for almost every recent version of CK no issues on my phone