
The iTunes' App Store offers iPhone and iPod touch users hundreds of
applications to install on their devices, but power users who want
functionality above and beyond what Apple's SDK allows still want to jailbreak their device.
Now that jailbreak developers have had a full month to work on
applications for jailbroken iPhone 2.0 users, there's a bigger
selection than ever of jailbreak 2.0 software that lets you do things
App Store offerings don't. Let's look at a few of the good ones.
Note: Most of the iPhone 2.0 jailbreak offerings are geared
toward the developer and power user. If you're not sure whether or not
you want to take the plunge and jailbreak, hopefully this post will
give you an idea of whether or not it's worth it for you.
This weekend I re-jailbroke my iPhone running the 2.0.1 software using PwnageTool. Here's how to jailbreak iPhone 2.0 with PwnageTool for Mac; Windows users, you can use WinPwn to jailbreak iPhone 2.0.
PwnageTool added both Cydia and Installer.app to my device (pictured
right). Cydia and Installer.app are the two gateways to software
repositories for jailbroken devices. Next to each app below, I'll list
the source (Cydia or Installer.app) and the app itself so you know
where to find it.
MxTube Downloads YouTube Clips to Your Device (Cydia)
When
you've got a favorite YouTube clip you want to show all your
friends—but don't want to wait for it to download over the air—MxTube
comes to the rescue. MxTube can download and save YouTube clips to your
jailbroken device for watching when you're offline, out of Wi-Fi range,
or just using the slow Edge network. Great especially for iPod touch
users without a data connection. (Original post.)
Click to view MxTube's search interface, with options to stream the clip as usual, or download to your device.
BiteSMS Offers Cheaper Text Messaging (Cydia)

BiteSMS is a text messaging service that offers an alternative to
AT&T or your iPhone's SMS carrier. Buy text messaging credits at
BiteSMS.com (currently 10 cents per message, less if you buy more) and
install the BiteSMS app via Cydia on your jailbroken device. Then, to
send messages using BiteSMS instead of your plan, choose it near the
Send button, as shown. (Click the image to see a full-sized version of
what sending a text message with BiteSMS looks like.) The BiteSMS app
keeps track of how many messages you send via your default carrier, and
how many BiteSMS credits you have left, so you can decide which is the
most economical way to send a message.
Here are detailed instructions for installing BiteSMS via Cydia; you'll have to purchase credits at BiteSMS.com to start using it as an alternative to your SMS carrier.
BossPrefs Removes Icons You Don't Want (Cydia)

While you can remove bookmarks and other app icons from your device by
just tapping and holding, then hitting the X icon on them, some icons
are absolutely fixed on your iPhone or iPod touch—whether or not you
use them. Install BossPrefs via Cydia to get extra options for
configuring your device, including "Poof!" a section where you can
disable icons—even fixed ones like iTunes or Stocks.
Click on the image to see a full-size view of Poof, inside BossPrefs.
WebSearch Customizable, One-Tap Search Launcher (Cydia)

This is the app that got me to jailbreak my iPhone pre-2.0: a quick tap
way to search common engines beyond Google, like Wikipedia, IMDB, and
even Lifehacker. Adam
named this an app worth jailbreaking for pre-iPhone 2.0,
and it still ranks right there even now. (Not sure why this app isn't
available via the App Store; let us know in the comments if you've
found an equivalent there.)
Click on the image to see a WebSearch quickly query Wikipedia search in action full-size.
gTxtEdit is an Actual Text Editor (Installer.app)

If
you want to store your notes in actual plain text files—instead of the
BS built-in Notes application—you want gTxtEdit. Granted, gTxtEdit
doesn't offer a file browser for easy loading and saving of files, and
to get your .txt files off the phone you need to SCP in (with OpenSSH,
see more below), so it's not the most user-friendly of apps. But plain
text lovers not afraid of the command line will dig it. (Also,
the developer promises that an actual file browser is forthcoming.) Click on the image to see a text file in gTxtEdit.
Customize App Skins Your Device (Cydia)

Users
who really want to trick out their device want to put a good-looking
skin on it. Using the Customize app, you can browse, preview, and
download custom skins, and apply the whole skin to your device or just
parts of it. Here are a few skins you can find there.
Click each image below to see it full-size.
From left to right the skins shown above are: AlienwareTheme,
Leopard, SketchedOut, and Stickers. (Be warned: I had some trouble
applying some skins I tried out, like Alienware. To activate a skin, on
the skin page, after you choose "Apply Theme to Device," head back to
the Customize main menu and choose "Exit & Restart Springboard.")
quake4iphone (Cydia)
This one's pretty self-explanatory. It's
Quake! On the iPhone!

OpenSSH Gives You Full Root Access to Your Device
We've been over this a million times already, but an article like this
can't go without saying: Getting SFTP (or SCP) access to your device
means you can move files back and forth from it. This lets you
copy voicemail or music files from the device to your computer,
transfer NES emulator ROMs to play on your device, access the text files you're editing with gTxtEdit, and
get your computer online using your iPhone's data connection. You can even do nutty stuff like
transfer your Notes and SMS messages back to your computer for saving and archiving with OpenSSH installed.
Of course, the previously mentioned Mobile Terminal and the NES emulator are also top picks for jailbroken iPhone 2.0 apps. The very promising SynchStep—an
app that purports to switch the song playing on your iPod to your pace
using the device's motion detection—didn't do as well as we hoped in
tests. (But the concept is super-cool, and we hope the developer will
work out the screen lock kink soon.)
What are your favorite jailbreak 2.0 apps, skins, add-ons, and tweaks? Let us know in the comments.
credit - http://lifehacker.com/400148/iphone-20-jailbreak-apps-you-cant-find-in-the-itunes-store