>Tiktok grabs your IMEI number, amongst numerous other things and sends them back to the mother ship.
Maybe I misunderstand you but the quick search[0] I did on Google says Apple iOS API doesn't allow programmer to fetch IMEI number. Did TikTok find a way to circumvent this and get the IMEI?
[0] https://stackoverflow.com/questions/41278494/how-to-get-imei...
[1] https://stackoverflow.com/questions/19927160/finding-imei-nu...