I am starting a compatilbity list. I will do my best to updated it as I get more information and as updated apps come in. First off, most all regular apps should work on 3.0. The changes were not that severe for most apps to stop working. So if the app is not in the list, it probably works.  What probably does not work are apps that rely on mobile substrate or any sort of springboard patching. These all use undocumented APIs.

Next is to understand why some things are not working *for you* that are listed on the “working” list. Many apps require root access and use a trick that involves the dirname command. This command was not present in some older packages in Saurik’s older repository. Saurik set up a newer version of his repository for 3.0 (which will merge back in to the trunk soon). The point is, many of you may have his older repository instead due to one of these reasons:

1) You used an early Icy without its essential updates that do not fix saurik’s repo.
2) You used apt backup to restore your packages and it restored the old repository.
3) You did not accept some essential updates.
4) Some other thing that I am not aware of. But the cause is most likely failing dirname command.

You can check if you have this issue in Cydia: Load Cydia, wait for it to do its thing then go to manage, sources, then look for Telesphoreo in the list. If you see this line of text *exactly*, you have the new repository “Distribution of Unix Software for iPhoneOS 3″ (this is good!) If you see this line: “Distribution of Unix Software for iPhoneOS” (this is bad) you have the *old* repository.

One more thing. If you install something and get an immediate spinning wheel of death, reboot. Some times mobilesubstrate’s install causes this and after a reboot it will be fine.

On to the app list:

Not working (* means not confirmed by me):
BossTool
Clippy
5 row springboard
*5 col springboard (some say this works, others not)
FontSwap
Homework Planner
iBirthdays
*iKeyEx and addons.
Quickgold – being worked on as an integration into spotlight.
Lockdown – being worked on
LogoMe – dev team is too busy
*Mobile Finder
MySMS
Notifier – status bar messages dont go away
*PwnPlayer
SBSettings AutoLock
SBSettings Close Button
*SBSettings User Agent Faker
SBSettings Volume MC Widget
*Scrobbled
*Scrobbler
Swirly MMS
textreader
*Videorecorder 3
Winterboard – Works except keyboard theming does not work.

Recently updated and working:
AptBackup – Updated to avoid overwriting saurik’s repository, but not tested by me.
Backgrounder – Now has a special version for 3.0.
BiteSMS 4.0 or newer
BossPrefs v3.0.1 or newer
ClearCam 1.1.2
iBlacklist 3.0-1 or newer. (I had a packaging error in 3.0)
Insomnia 3.0.2
iRealsms – Working
irealquicksms
MobileDTA 3.1
Mobile Substrate – This is foundation for many apps like SBSettings & Winterboard. Recent bug was causing iTunes store to not load.
NibbleSMS – updated and working now.
Safari Tab Closer v1.2
SBSettings iPod Widget 1.2-1
ScreenSplitr

Working (not complete):
Everything should work, so if it’s not on this above lists, it should have been working all along.

Upgrading in iTunes on a jailbroken device has become rather complicated in order to avoid problems. I have made a step-by-step guide to help in this process to help you understand the proper way to upgrade. For the purpose of this guide, I will use as an example upgrading from 2.0.2 to 2.1. However, the concepts apply to any upgrade.

First off, if you have never jailbroken, you don’t need to worry about this guide. Just hook your iPhone up to your computer and tap the “upgrade” button and wait. That’s it! Now proceed to the jailbreak guide of your choice.

The complications come when you have a jailbroken device and you want to upgrade. Say you are running 2.0.2 and have a lot of Cydia apps installed. You want to upgrade but you don’t want to lose these apps. You may have a lot of customizations, icons hidden, and other things. If you upgrade, you will find your hidden icons are still hidden but the apps required to unhide them are not yet installed. Here are some steps to help:

First off, you never use “upgrade” on a jailbroken device. If you do that, you automatically lose about 500mb of disk space and never recover it until you finally restore. If you upgrade from 2.0 to 2.0.1 using upgrade button, you lose 500mb. If you then upgrade from 2.0.1 to 2.0.2, you lose *another* 500mb. And this continues until you hit the restore button. The data loss is because Cydia moves your files around to free up space. The moved files become inaccessible but stay on your disk which means you essentially just lose the space. The more apps you had installed in Cydia, the more space you lose.

The solution to this is easy. Restore, do not upgrade. Here are the steps that you should take on a 2.0 device to upgrade without any loss or issues:

Step 0) Before starting, upgrade your iTunes first. If you are moving to 2.1, you need iTunes 8. Upgrade that now. You can get all iTunes versions for Windows here.

Step 1) Install aptbackup from cydia and run it to backup your apps. This will make a list of all your cydia installed apps and put the list in a location that can be backed up by iTunes in step 2.

Step 2) Sync with iTunes. Do the full backup. It may take you a while on 2.0 – 2.0.2 but you need this step. Go get dinner or coffee or watch a movie. Come back when it’s done. If you disabled backup in iTunes then you can still backup by right clicking on the device under “Devices” on the left and selecting “backup”. Do not get impatient and interrupt the backup. If you do, it will be corrupted and useless. You would lose everything on your restore.

Step 3) Restore your firmware. If you are upgrading to the latest version of firmware you can just let it download and restore. To do this, click “restore” and wait. If you would rather download the firmware manually, you can get all firmwares here.

Step 4) At this point, if you are a contract subscriber (AT&T or such) you need to activate your device in iTunes. Just hook it up and wait, it should auto activate allowing you to slide to unlock to icons. If you are unlocking, you probably see “slide for emergency” only. Do not do anything else in iTunes at this point. Disconnect your device from your computer. Do not restore your backup, do not set up as a new phone, just remove the device.

Step 5) Do not restore your backup in iTunes yet. Instead, jailbreak your device now. I suggest using quickpwn. You can follow my guide here.

Step 6) Using Cydia, install aptbackup. This is the most important part, do not skip any of it. The rest of this step will allow you to correct any problems you encounter in the next steps.
a) Install open SSH.
b) If you had 5 icon dock installed before the upgrade, install that now also.
c) Install BossPrefs

Step 7) Restore your backup from iTunes. Just hook back up to the computer and when asked, restore as a backup from whichever iPhone you had.

Step 8) iTunes will restore your settings, contacts, notes, pictures, and all your apps. Now to restore the rest of your Cydia installs. Open aptbackup and hit restore. It should reinstall all your packages from Cydia. If aptbackup is now hidden (missing icon) after your iTunes restore, load BossPrefs, go to hidden icons, and unhide it. You can also unhide any other hidden icons here.

Step 9) If you had a bunch of category folders and moved most things into it, the iTunes backup will have made these icons disappear. You  can unhide them via BossPrefs.

For any help not listed here refer to my other post describing the issue in greater detail.