Is there a way to make your phone automatically turn off data when you arrive home (since would then be using wifi and don't have unlimited data). Even better would be if you could also make it turn data on when you leave home.
Tasker could certainly do that. Also, most phones should automatically turn off mobile data if a wi-fi data connection is established--so if you had wi-fi on all the time, it should automatically connect once you get home, thus shutting off mobile data. However, I have read complaints about certain devices still using mobile data, even when connected to wi-fi.