SGS2 I9100 Guide: Must Have Rooted Apps

After you flash your SGS2 with custom rooted kernel, you might want to ask, what kind of apps which actually utilize root.
I believe apps such CWM Manager, and Superuser should be available with most custom ROM out there, so i won't describe it anymore.
Here's some apps you might find useful

1. File Expert FREE
I use this app as a root explorer, and also as FTP server to access my phone from PC (under wifi).
But the most important thing is SMB file sharing to access my Windows 7 PC from phone, which work flawlessly with my wifi router.
You can stream mp3, m4a and also mp4 movie with web optimized profile, e.g. downloaded from Youtube.
Just enter your PC IP address, username, and password (username must have password) and you're all set.
At present i use the older version, 3.2.7 to be exact, since i'm having problem accessing the /data folder using the latest 4.0.X version. 
*If you still want auto log on to your PC, type "netplwiz" on search, run, and untick "Users must enter a username and password to use this computer.".
This way your PC will auto log on at start, but you have to enter password when you log off.

2. Voltage Control FREE/PAID
This app is for the performance seeker (overclock) and also for powersaver.
you can change the I/O scheduler, CPU governor, voltage and bus, GPU clock and voltage, and charging current.
The Extreme version allow you to set even lower/higher voltage, view CPU history, and the most important thing is the profile management.
Yet it has disadvantage from SetCPU such no automatic profile based on criteria, i.e. low battery, sleep, heat.
Here's my voltage setting which best suited me:
CPU 100MHz@800mV, 200MHz@850mV, 500MHz@900mV, 800MHz@950mV, 1000MHz@1050mV, 1200MHz@1150mV, 1400MHz@1250mV, 1600MHz@1350mV.
GPU 160MHz@800mV, 267MHz @950mV, 400MHz@1100mV

3. Set DNS FREE/PAID
To change your DNS. The simple answer is that some network provider use their own DNS, which may block some website. I prefer to use Google DNS.

4. Market Enabler FREE
This apps is very useful when your region not having special offer/free apps like other region.
It works not only on Android Market, but also on Samsung Apps.
For example, in my country NFS: Hot Pursuit is not available on Samsung Apps, but if you change to Germany provider, you can download it for FREE.

5. AdFree FREE
As described, to remove ads by editing your host file. In some free games, you will still see the ads though.

6. Chainfire3D FREE/PAID
This apps is useful for GPU performance customization and also games compatibility with different hardware, such PowerVR, Tegra, and Adreno.
You need to install the BETA driver to make MSAA work.
The pro version allow you to enable per app profile, enabling you to use MSAA, for some games it does provide visual enhancement, i have done a review of this apps in here..
I haven't tried the GPU plugin, so i can't say anything about that, though it states that it will enable market device specific to be unlocked.
I have a problem with the CF3D driver recently, it seems that the driver in XWKK5 ROM not working well with stock browser, it force close when i use the driver.

7. BLN Control FREE/PAID
This app use key backlight as notification which is very useful to notify for incoming message, IM, email, even missed calls for pro version.
You need to have supported kernel to enable this feature. To make stock Messaging app to work, you need to flash services.jar.