I was recently trying to view an HTML 5 application using the browser on my AT&T Samsung Galaxy S2 and found out that I couldn’t.  Upon doing  a Google search, I found that the most likely reason I couldn’t view the application was that I didn’t have the latest firmware on my S2.  I quickly went to Settings > About Device and found that my Android Version was 2.36, which is known as Gingerbread, not the latest 4.1, which is known as Jelly Bean.

I tried doing the over the air upgrade, but I kept getting a message that I was was on the latest version.  I then found out that in order to upgrade to Android 4.1 Jelly Bean, that I needed to download Samsung Kies.  

Upon installing Samsung Kies, I was then able to plug in my phone using the USB data cable and it gave me the option to upgrade the firmware to 4.1.  I recommend backing up your phone before doing this.  You can do this easily using Kies.  Once you’re backed up, go ahead and upgrade.

After upgrading you’ll get a message to pair your device with AT&T, which you can do, but I didn’t since I already have everything synced up with my Gmail account and Google Play.

I found that upgrading to Jelly Bean got rid of some the slowness and choppiness I was starting to experience with my Galaxy S2.  A friend of mine said the same after I helped him upgrade.  I really like the new interface, especially how the layout of various screens.

If you haven’t upgraded yet, I recommend that you do so soon.