Facebook, AT&T and others are helping to add voices, texts to apps

Although Facebook's (NASDAQ: FB) $16 billion purchase of WhatsApp is probably the highest profile action in the space, there are a wide range of companies looking to cash in on the opportunity to add texting and voice calling to apps. For example, AT&T (NYSE: Trecently hosted a full-day workshop offering help in deploying its speech and messaging APIs. And WeChat released its own open API to allow third-party developers to tap into its network.

But it's early days in this space, and there are a wide range of services that companies are looking to offer. For example, Plivo is looking to offer prize notifications and coupon redemptions via SMS to game makers for in-game awards and purchases.

For more on this topic, check this FierceDeveloper special report.