DeepAffex Extraction Library
The DeepAffex Extraction Library is a low-level library used to extract facial blood-flow information from a sequence of face-tracked images using a technology called Transdermal Optical Imaging. It is available on three desktop platforms (Windows, macOS and Linux) and can be downloaded from the DeepAffex website. It has bindings to several popular programming languages made possible by its C API which facilitates linking with C Foreign Function Interfaces.
The library is canonically documented in the C/C++ documentation.
On iOS and Android, blood-flow extraction is managed by the higher-level Anura Core SDK. On the web, it's managed by the the Web Measurement Service.