Text messaging is perhaps the most popular way to communicate with friends and family in the world. The iPhone has the built-in Messages app, but what if you don't like it? And what about the iPod Touch? It doesn't have a phone.

In either case, you’re in luck. Because texting is so popular, there are a ton of great free texting apps for the iPhone and iPod Touch. These are especially great if you have a Touch, since many apps assign you a “phone number” that you can use to send and receive texts, photos, and more.

These apps are free, so what's the catch? Many of these free apps have a lot of ads, but that's probably a minor inconvenience in exchange for unlimited texting (in-app purchases often remove ads and unlock extra features). Keep in mind that you'll need to connect your iPod Touch to a Wi-Fi network to use these texting apps.

WhatsApp is perhaps the most widely used text messaging app in the world, which is one of the reasons why Facebook invested in the company for $19 billion in 2014.