How to find the lost mobile when no tracker app is installed?
Have you heard of plan b ?


  Plan B is your last resort to find your missing phone. This is the
  first and only 'find my phone' app that you download AFTER you've
  already lost your phone. Having Lookout on your phone is the best way
  to protect your phone and find it fast, but use Plan B if you have
  already lost your phone and didn't have Lookout installed.


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NOTE: Plan B only works with 2.0 - 2.3 versions of Android
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