Nokia has launched a new app for the s60 V5 that I find quite interesting. Nokia Diagnostics was launched by betalabs and it is one of the most useful apps I have seen from Nokia.
This app is designed to run troubleshooting on the phones hardware and software. It determines whether your phone works in its optimal parameters. The first release is not for 3rd series Symbian but it is announced that it will come soon.
This first release has five test that it runs :
1. Network Coverage test
2. Internet connectivity test
3. Battery charger test
4. Loudspeaker &
5. Earpiece test
Hope that when it is released for the S60 V3 it has a bluetooth test for as we all know that is the most pressing issue with the E75.

