Free calling and texting apps face a triple threat to long-term viability

The list of apps that offer free texting and voice services on iOSdevices grows longer every day. Viber is one, as is Vumber, which now provides cross-platform Android and iOS calling.

These apps have a noble goal: provide users with an alternative to managing costly voice and text plans from carriers in addition to the data plans they must have in order to take advantage of everything smartphones have to offer. But they also come with a big downside; these apps are only as strong as their network of users, (since in most cases, free calling only happens between users who have the same app installed on their device), and as the data network that allows them to exist.