To fix stuttering issues in 4.3:
1) Jailbreak with redsnow and install iFile from Cydia (Free trial version works)
2) Open iFile and find system/library/coreservices/springboard.app/N90AP.plist (N88AP.plist for 3GS)
3) Open file and find the lines:
<key>launch-mode</key>
<string>pre-animate</string>
Replace these lines completely with:
<key>launch-applications-while-
animating</key>
<true/>
4) Save file and restart the phone, or respring with SBSettings.
Your animations will now be smooth, and the apps will load while animating.
Side Effects:
1) Joy and happiness as you once again have a smooth running phone.
2) Sometimes when switching back to an app, the status bar will briefly flash black then white. Its near instant and has absolutely no effect on anything and thus does not matter.
3) If you open Cydia, do nothing and quickly close it, then reopen it, it will not open. Clear Cydia from the multitasking tray to fix. Since Cydia wil restart/respring the phone with every tweak you install, this literally only affects you if you like simply opening and closing Cydia over and over again within a 2-3 minute window. That should be absolutely no one.
OK, so this is just plain bul**hit (sorry for that)
I restored back to 4.3.3 to try what you wrote so I jailbroke
With redsn0w rc16, first I must say that at that point the stutterings were a lot less than what I remembered.
Then I installed MobileSubstrate from cydia and found that this caused the stuttering to get worse.
Then I tried the plist editing and here are my thoughts about it:
a. Replacing the two lines of the launch mode with the old lines of launch while animating does exactly the same as just removing them
b. It's more placebo effect than anything else, apps launch and exit animations still stuter alot
c. The status bar flashing is nit that quick and is very noticeable
And it does not happen "sometimes" but happen everytime that
you open an app from the multitask bar when the app has already been loaded.
My conclusion is that this hack is nice to play with but it really does not solve anything, in my opinion, this is s mobile substrate issue that is not compatible with the new springboard.
Again, sorry for the criticism, but had to say what I think.
I'm planing on restoring again, just not to install mobile substrate and
See if it's helping
Thanks,
Jonathan