 
1. Aircrack-ng for IPhone:
It
 is the simple command line with graphical interface software which is 
used to crack wifi networks . It sends packets to the wifi network and 
then cracks the password file of the network .It is used widely and can 
be downloaded from 
here.
2. IWep Lite:
It
 is an Iphone applications which let you crack wifi network in less than
 30 minutes . It is easy in use and can be understood easily rather than
 Aircrack-ng . It is Graphical interface with best utility and 
dictionary . Apart from Aircrac-ng it uses dictionary and so it is less 
trustworthy than Aircrack and can not crack every key. It is used more 
widely than Aircrack but it uses dictionary that's why it is on 2nd 
number. It can be downloaded from 
here .
3. WepGen:
WepGen
 is just another application which cracks the Wifi network by sending 
packets and it is rather easy in use than Aircrack but though it is on 
3rd number due to it's popularity. It can be downloaded from
 here.
4. IWifi Hack:
It
 works on the same scene as other cracking softwares except iweplite 
means it sends packets and break in the security of a wifi network . It 
is easy in use and can easily be used by anyone. It can be download from
 
here.
 
 
- See more at: http://www.hackersthirst.com/2012/01/four-best-wifi-cracking-applications.html#sthash.elQnG1YO.dpuf