State Bank of India fall in the list of biggest banks in India. Being a Nationalized bank it requires a lot to make the quality upto the mark. The app is not as good as other private bank but you can go ahead using some really basic functions. SBI has named its app as SBI Bank Freedom. To use that you have to first register yourself on the bank service. Or else it will not work.
You have to also register your mobile number for that. Just send MBSREG to 9223440000 to get a user id and a mpin. You will get this only on your registered bank account. Then you can login using the user name and mpin. The app help you for imps, fund transfer, balance enquiry, bill payments, etc. The app faces compatibility issues. So you have to check that first. If it not working then remove it.