Scheme Droid is a free, open-source utility and tool available on the Android platform. It is a minimalist, multi-paradigm dialect of Lisp that implements all of R4RS Scheme. However, continuations can only be used as escape procedures, and strings are not mutable. It is powered by the JScheme library, which makes it a reliable and robust interpreter.

Scheme Droid is a useful program for those who want to learn and experiment with the Scheme language on their Android devices. It is designed to be accessible and easy to use, making it an excellent tool for beginners. It is also well-suited for experienced programmers who want to experiment with Scheme on a mobile platform.

Overall, Scheme Droid is a great program for anyone interested in learning or experimenting with Scheme on their Android device. It is free, open-source, and easy to use, making it an excellent choice for both beginners and experienced programmers.