So in continuation of my rant on the SDK and firmware v2.0, I decided to compile a list of existing iPhone applications that I believe would be impossible or not allowed on the SDK. This is to give you an idea based on existing applications what types of things could not be done on the SDK or would not show up in AppStore, ever. In short, if you like these apps, plan on jailbreaking. Note, this is not a complete list.

Remember, there is nothing technologically limiting about the SDK, itself. Instead, it’s Apples distribution policies that make these apps impossible. So while the developer could program them, they would never be able to appear in AppStore with the current limitations set by Apple.

Apps that can not be written with SDK and distributed in AppStore:

Ants – Tis toy where ants are crawling around your screen violates the SDK rule about leaving a process running when you press home.

Appsupport – You live in a non-supported country and you want to patch your language? Tough luck. Requires system file access.Apache / LightFtpd – Like these web servers? Think they’re cool to run on your phone? Apple doesn’t. They will be shut off as soon as you hit home. Nothing is allowed to stay running. Not too useful like that.

Apollo IM – Nice instant messenger app. It would be ruined on the SDK because of the requirement that no app can stay running when you press home. You would have to reconnect each time you loaded the app. Everyone would see you as offline in the meantime. Worthless.

BiteSMS/SMSD etc - All these SMS applications will be crippled on the SDK as they would only allow you to work in the app but not stay running to receive SMS messages when you press home.

Bookmarklets – Nope, you’ll have to enter them yourself. Good luck with that.

Bootneuter – Any unlocking will be impossible, obviously.

BossPrefs / Services / iToggle / NetServices – All these are great (of course BossPrefs is the best one!). They save so much time and so many button clicks. Too bad you will be unable to use them on the SDK. They all require system access.

BossTool – Think you want to move things around to free up more space for apps? Too bad. It won’t be happening. However, it sounds like Apple is giving you 500mb instead on the host partition. Let’s hope it’s enough because there won’t be any non-jailbreak way to fix it.

Categories – Make folders on your desktop. Nope. Requires system access in order to make the folders and to hide apps.

ColloQ / iRCM – These irc clients are very nice. I love using IRC on my iPhone. Unfortunately, as soon as I press home to do anything else, they would have to close. You would have to reconnect to all your servers. How annoying.

Customize – Everyone likes to customize their images. This is not allowed on the SDK because it modifies system files and would need root access.

Dock – This is Nate True’s application launcher that sits as a little light burst. It is not allowed on the SDK because it’s a process that runs after you press home.

Docs – This relies upon Safari’s ability to display a local file. Apple does not allow for that. Patching safari browser would not be allowed. Not only that, but no way to put docs onto the phone. This also includes apps like Wild Eyes that run a server in the background to read the docs. Remember, SDK does not allow anything to be started and remain running when you leave the app. Therefore, the server would be killed as soon as you launched safari to view the doc.

Hidepod – Lets you hide apps behind a password. Nope, requires modifying system files. Forget it.

iAmp / Audio Amp – These amplify speaker volume. They’ve never worked for me but some claim success. Anyways, it won’t matter because they modify system files. You won’t be doing this with the SDK.

iRadio – Wow shoutcast on the iPhone. This is great! But again, Apple will not allow this to continue to run when you press home. So forget listening to the radio while doing other things.

iSlsk – This is the iPhones first p2p client. There are multiple reasons this is impossible on the SDK but the first and foremost reason is that Apple allows no app to continue to run when you press home. So this app would run for the few seconds you were staring at it but as soon as you did something else all your downloads would stop.

Mobile Chat – This is a fantastic AIM, MSN, .MAC, ICQ chat client. It will be possible to run but Apple will not allow an app to stay running when you press home. So it will only run while you’re looking at it. Each time you press home you will have to relaunch and reconnect to the servers again. Makes it worthless.

Mobile Finder – You would only be able to browse files that are within your user dir. It would be hugely crippled.

Mobile Scrobbler – This has a daemon component, forget it.

Mobile Term – The latest terminal is really fantastic. Unfortunately, there’s nothing you can do in a term window that Apple will allow on the iPhone.

MXTube – This is a youtube video downloader. Breaking youtube encryption without authorization? I don’t think so.

NES/SNES/GBA emu etc – Technically, these could be made to work on the SDK. But there would need to be a way built in to upload ROMs. And I would speculate that Apple would not allow such an app on the SDK for other reasons.

OpenSSH - This requires BSD Subsystem which cannot be installed, full file system access, a daemon, so there are 3 reasons this cannot appear on the SDK.

PocketTouch – I love this app. You can start music and let it run and use this app to change songs by shaking the iPhone. This app will work but be crippled. It would require the app to always be running on the screen and as soon as you tried to go do something else, the music would stop playing.

Poof – Like hiding icons you don’t use? Too bad. With the SDK you’ll be stuck with them all. This requires system file access. You won’t be able to do it.

Safari Patch – This let you use file:// in safari to view local files. Can’t modify Safari binary.

SendSong – This app has several features. One is sending a song as a ringtone. Unfortunately, many of its features requires system level access. You won’t be allowed this on SDK.

StatusStyle – This let you change your taskbar’s appearance. Unfortunately, it requires system level access and cannot operate with the SDK.

SummerBoard – Like themes? There’s no way that this one will be on AppStore. It violates many rules such as requiring system level access, modifying system files, hijacking into SpringBoard, etc.