In short, don't buy a TCL flip!! I bought one to help curb my smartphone addiction but the results were terrible. The TCL flip doesn't run kaios, it runs aosp.. and by default it doesn't let you install 3rd party apps and has no app store.. this is retarded on TCL's part because it makes having a quad core CPU, 4g, and wifi completely pointless.
I used the method on this forum (neutron.img) to enable pushing apps from adb and it was still terrible! Unlike kaios the apps aren't designed to run on a small screen without touch so trying to start a new convo on Whatsapp means using the buttons to scroll past a billion convos.
This is just an example, ofc I'm not saying that all feature phones should use kaios, but there's no benefit to owning this phone over my bb q10 from 15 years ago. In fact the q10 is much more useful. I didn't need a full blown play store, I have my S22 Ultra for that, but without WhatsApp and Google maps (less importantly) I simply couldn't work. As such, this phone is E-waste and strongly unrecommended by me.
