Of the tools and services for developers we asked about in our last survey, one category stands out by miles as having the wealthiest developers: voice services. Of course there’s a lot of variety in the voice services sector and the revenue is not at all evenly distributed.

Voice communication is one of the core functionalities of every mobile phone. However, telephony is up for a big shake-up, as Internet telephony companies like Skype and voice application platforms like the ones below are challenging century-old assumptions about how people speak with each other remotely. Voice Application Platforms allow you to make creative solutions that integrate voice communication deeply in your app: as voice messaging, click-to-call, person-to-multiperson, voice search and more. But despite catering to many use cases, their use is relatively low among developers. An opportunity to stick out of the pack?