HeyWire uses an alternative phone number, but it doesn't include free voice calls. Furthermore, the interface is colorful and engaging, but it's not the easiest to use. Case in point, the app lets you tweet, but only over SMS. Also, there's no option to integrate your phone's native text service. Still, HeyWire has something to offer. There's Facebook Messenger, customized SMS signatures and an on/off setting for new message notifications. Oh, here's something you won't find in other text-for-free apps: customizable, pre-saved text messages for in-a-pinch scenarios like driving or when you're on an airplane.