Follow along with the video below to see how to install our site as a web app on your home screen.
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It should be on the carton the phone came in, assuming you've got that. Also you can do *#06# from the dialler, that will show the IMEI.
Settings -> About Phone -> Status
Did you go to the Status page in About Phone? That's the default location, and here's a video for the Galaxy S6:
MEID is for CDMA phones, IMEI is for GSM. I think newer CDMA phones also use IMEI now.