Tropo is a cloud-based API for adding voice, SMS, IM and Twitter support to programming languages. The service runs on telecommunications company Voxeo's infrastructure. You can use Tropo to build voice operated phone menus, automated VOIP applications, voice mashups, SMS applications and more. Tropo is free for development. Once an application moves into production, customers are charged per minute for voice services or per message for SMS services. Customers pay for only what they use.
Amber Case and Aaron Parecki, the co-founders of Geoloqi, use Tropo for their project. The pair cites features, scalability and support as the main reasons they choose Tropo.
In a post on the subject, Parecki notes that "In addition to sending SMSs and calling phone numbers, Tropo can send messages over other text channels such as AIM, Google Chat, MSN, Yahoo IM, Jabber and Twitter, and can also call Skype and SIP numbers."
Tropo also allows users to set outgoing phone numbers to any number they want.
"In terms of scalability - Voxeo's network has been built out over 10 years," says Case. "We know that what we build on it will not only be very strong, but it will be able to scale well."
The two say that Tropo's support is always available via IRC and are extremely approachable.
Tropo costs 3 cents per minute for voice services, 2 cents per SMS message and $3 a month for each phone number.Full pricing information can be found here.
Tropo was founded in 2009 and is based in Orlando, FL.