Depending on the company, converting music into a tonos de llamada can cost money and require technical expertise.

However, a new app from Verizon will let users pay $2 per month to download a large selection of ringtones and ringback tones sourced from Slacker radio. The app, which is exclusive to Verizon subscribers, can be used to assign different ringtones and moods to each of your friends and family members.

It's a great way to expand your ringtone library without paying extra for each song. It's also a way to help support your favorite artists and bands.

You can't get much more personalized than a set of ring tones that says, "I love you," or "Me and my girlfriend." But did you know there are dozens of apps on the market that give you even more control over your phone's audio output. And while most of them charge a monthly fee, one stands out as a true steal: Slacker Radio Tones from Verizon.

First, it's a big deal because it's the only application to offer a wide selection of high-quality, symphonic ring tones (which are also available for download on Windows phones). You can assign different ring tones to each of your friends and family members, and you can even create custom ringback tones that play when your phone rings out for someone else.

The snazzy-looking app is free, but it requires an active Verizon Wireless account and a subscription to Slacker Radio. You can change your ringtones as often as you like, and the app's library of tones is constantly growing.