The major breakthrough to make this happen was the developers of MJMD5; DTM, Stewart, netdata, az1234 and teddy_b that resides/ed on magicjacksupport.
read more about the code here, notably pages 3- 7: MJMD5 concept and coding.
The original softphone code is by Regis Montoya, alias r3gis.3R, and his crew: CSipSimple
It has been modified to support MagicJack in collaboration with Spider210: CSipSimpleMJMD5
r3gis made the following remark:
Magic Jack authentication method is now integrated to the trunk of the android port of pjsip. As consequence all future release of CSipSimple will include the Magic Jack feature
The concept has been tested both on 2.2 and 2.1.
The easiest way to obtain your MJ Sip credentials is:
MagicSipac, by kiler129 based on genexweb and stroths work
a variation made by Michael LaSalvia, alias genxweb, based on initial work by stroths is MJSIP - updated method 10/22/2010
for more detailed info of how to use this, see MJSIP details
And, if you like the product, don't be shy. Support the developers Donate!
Sorry, I couldn't figure out how to attach the files, why you have to go and get them yourselves in the links above