Is there a way to to manually install ad hoc provisioning profile on tester device without using iTunes, XCode and apps like TestFlight?
EDIT: I followed the solution suggested by Max and the process of sending the certificate via email seems sensible. However it does not work for me as it says "Invalid certificate".
However it should be valid as I signed the certificate with a correct key (it used to work till last week and will expire only in May 2014). The device uuid entered in the certificate is correct. No idea on how to fix this.
Here is the screenshot taken from the tester device (text is in Italian and says "Invalid profile"):