I was using linphone for a while, and for 2 weeks I am using linphone for android on a nexus one phone
I have tested several applications for the iPhone 3GS and for the ipod Touch and I found that linphone has some drawbacks. Here are some options you should consider for the next generations of the software :
1) There is no pop up when receiving a call (when using the android version). 2) There is no icon in the bar on the top of the phone indicating if the linphone application is running. Such a icon should be very interesting when using the application with a wi-fi connection. The icon could change color if the registration to the sip server is ok or not.
3) Is it possible to include different ringtones for different users using linphone ?
Other than that, the application is great. Thank you for your time.