For the last couple of months I've been testing a app on my Android that let's you pick another line/number (in any area code) to use. It does use your existing plan minutes so this is best used with unlimited plans, which most of us have nowadays, anyway. The quality is good since it uses your existing phone service and doesn't hog much of your data. I'm pretty sure there's an iPhone app, as well. The free version has rather large ad when you load up the app but for 2.99/month you can do away with that and have other features, too. If you stay with the free version then you have to make/receive a call at least once a month in order to keep your same phone number. Look for "Sideline" on Google Play or in the App Store. Of course, you can still use Google Voice if you have that set up already. On my phone I now have 3 lines. Not that I need all these lines...I just think it's kinda cool. It's also a great way to harass people at 3am.