FaceBlend is a fun and user-friendly app that allows blending of two faces into one. Here is an overview of its main features:

Facial Detection & Mapping
At its core, FaceBlend utilizes facial recognition technology to automatically identify key facial landmarks (eyes, nose, mouth, etc.) This allows precisely mapping faces in the input photos to enable accurate blending.

Customizable Blending
Users can adjust the degree of blend from 0 to 100% to determine how much each contributing face impacts the end result. More advanced localized blending controls are also available.

Symmetry Preservation
Special logic ensures both halves of the final blended face retain symmetry. If one source face is smaller, the app intelligently centers and fits the two faces avoiding unnatural distortions on one side.

Creative Blending Modes
In addition to a straight fade between faces, FaceBlend offers artistic blending modes like "ghost", contour shading and more. This expands the creative effects possible.

Social Sharing
The app makes it easy to save your unique blended creations and share them with friends through all the major social/messaging apps straight from FaceBlend.

Overall, FaceBlend puts an easy-to-use interface on a technically complex process of realistic face blending. What used to require professional image editing skills is now available to anyone interested in creating their own unique facial combinations from two people's faces. The results can be eerily realistic!