The app is easy to download and install. Easy to configure with the free SIP service I get from Pbxes.org and Google Voice. Easy to make calls, easy to receive them. I was trying to use the soft phone to dial into a conference call, and at first I thought there was no way to add DTMF tones to a call in progress. In the discussion forum, I discovered that you can type the numbers when the cursor has focus on the window for your call in progress. But there is no user feedback to indicate this capability exists, so you have to type the numbers blindly and nothing happens until you hit return. I would prefer a keypad graphic and local audio for the tones as the keys are clicked. Performance is great, price is unbeatable. Nicely done, Mr. Kuznetsov!