Among the offline navigation options in Android, I have been told the best is Sygic. I have tried it, but was terribly disappointed as the damn thing is bloody confused. It just doesn't recognise U turns or mid sized roads branching out, and I couldn't see an option to set it either
well. considering windows phone devices do not offer dual sim functionality today, you are pretty much stuck with android or symbian devices.
i could suggest a simple thing... a 98 rupee monthly plan would offer enough bandwidth for google maps to work. but it is of course not true navigation as google does not offer voice support.
Nokia maps is supposed to be the best offering apart from third party services like mapmyindia. i do not think mapmyindia currently has a functional navigation app available on the google android platform.
MapmyIndia has Sygic at the backend but older versions.You can use the latest version 11 of Sygic directly which has hardware accelerated 3D maps rendering. One of the best Offline Maps app i have used. Has turn by turn voice navigation too. Most detailed for India. Has maps for many other countries also.Get it from here first >> ipmart-forum.com/showthread.php?718308-Sygic-GPS-Navigation-v11.2.1-v11.2.0-with-Maps&highlight=sygic (mod: warez? )Install, Don't register, else it will go to TRIAL version. Then download maps either statewise or for whole of India. Beware, the maps download size will be large depending upon what you choose, So using WiFi is advisable but it's a one time job.