SIM unlocking your smartphone allows you to switch your device SIM card whenever you want regardless of the carrier: from AT&T to T-Mobile, Orange to SFR etc. depending on where you live. The Samsung devices are usually quite easy to SIM unlock (see How To SIM Unlock the Samsung Galaxy S) and the Samsung Galaxy S 2 is no exception as Chainfire released an app called Galaxy S2 SIM Unlock which allows you to easily unlock your Samsung Galaxy S 2.
Before you can SIM unlock your Samsung Galaxy S 2, you will need to root it. You can follow our instructions @ Root Your Samsung Galaxy S 2 – How To.
Here is a quick description of this app by Chainfire @ XDA:
Galaxy S2 SIM Unlock code finder will find the SIM unlock code for your device, or the unfreeze code. It'll take a few minutes to run, but you should end up with the code to SIM unlock your device. If the code doesn't work, don't keep trying it !. You may end up with a freeze. In that case, the program can also find the unfreeze code, but if the SIM unlock code is wrong in the first place, maybe so is the unfreeze code
You can find the app Galaxy S2 SIM Unlock on the Android Market @ market://details?id=eu.chainfire.sgs2simunlockcode (Mobile) or https://market.android.com/details?i...2simunlockcode (Web).
You can also get the app on XDA @ http://forum.xda-developers.com/showthread.php?t=1092451.
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