I use both Skype (incoming number + outgoing calls to phones) and Magic Jack (MJ). Skype works well except the caller ID is usually some random number so your call recipient will always be pleasantly surprised that you are calling from Thailand or wherever. Skype has a Windows, Android, and Windows Phone version (don't know about Mac stuff). Skype on Windows Phone + WIFI: has excellent sound quality, but you cannot listen to voicemail. That is funny considering who owns Skype, eh? The Android version has voicemail. I used to use a USB-to-traditional phone gadget for Skype but its software never got updated from XP. It worked, except for typing numbers from the phone. Magic Jack on USB works with a slightly slow startup on Windows 8.1 and below. It's nice to use and old fashion heavy phone to speak with someone. You can use MJ for 911, unlike Skype. Caller ID is correct with MJ. MJ has an Android version. MJ has a hardware version for traditional phone set that does not require a separate computer and just plugs into ethernet. MJ voicemail gets emailed to you as a WAV file, which Skype does not do -- Skype only emails that there you've received a voicemail but you cannot hear it without Skype.