When I was using android phones only, I could switch back and forth between handsets (I'm on Verizon) by simply entering the ESN on the VZW site and then dialing *228 from the phone I wanted to use. The cool thing was that when I would resume using a particular phone, everything (apps, settings, etc) was exactly as I left it from the last time I used it.
Now I am using an iphone 4s. So my question is, if I activate my old android handset for a few days, and then want to reactivated my iPhone, will my iPhone let me take up where I left off? Will apps, settings, home screens, etc, be just like I left them, or will I have to start from scratch?
I would imagine it would be the same as it was with your Android devices. Still, to be on the safe side, I would do an iCloud backup or backup with iTunes beforehand.
How about on the AT&T network, I have an Atrix and got an iPhone 4s and went to the AT&T store and activated it and I also bought the SIM adapter. Can I switch back and forth or no? Thanks in advance.
OK, but when when I put the SIM back into the Atrix it wants me to sign into my Motoblur account, that isn't going to mess anything up is it?
Nope. You will be fine.
*Though eventually you may get a message from AT&T saying you are not on the proper data plan and for you to call them. You can ignore that if you'd like or switch back to the iPhone at that time with no worries.