view planet 3 on unlocked iphone?

[Michael]

hi, well atm im on a $19 plan on a nokia E63 with Three, i still hav 1 year left of my plan. i am going tp get an unlocked iphone 3gs and put my sim in there, wen i get the iphone am i still able to view planet three for free? since planet three is the only way to see how much of my plan i have left. i am also going to hand my E63 to my little bro so he can use it on prepaid. will he be able to view planet three? even if he goes with another network? many thnx