Twilio - Brings voice and messaging to your web and mobile applications.
Listen N Write - Listen N Write can be used to play and transcribe ordinary audio and video recordings (WAV, MP3...
Plivo - Plivo simplifies your customer engagement.
Go Transcribe - Advanced cloud based transcription service powered by artificial intelligence
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Podcast Transcribe - Convert Podcast to text, upload an audio file to get the transcription.