The e-SignLive iOS SDK by Silanis allows API communication to implement electronic signature features into mobile applications. Documentation offers server-side software and client-side software options in addition to users' instructions.
Handling API calls in the cloud with a service like AWS Lambda is one of the latest ways enterprises try to save on resources. In theory, you can save a ton of money. But be careful. Costs for API calls can mount up, sometimes leaving you with a cloud computing bill ten times the size you expected.
A summary of discussions from OKFestival on open data business models reveals a strong commitment to fostering an ecosystem, while many startups commence with a composite model with multiple revenue streams.