When a SMS is sent, save it to a Google drive document (each contact gets its own doc)

Create custom workflows effortlessly by selecting triggers, queries, and actions. With IFTTT, it's simple: “If this” trigger happens, “then that” action follows. Streamline tasks and save time with automated workflows that work for you.
13 triggers, queries, and actions
Android SMS is a native service that allows you to receive Short Message Service (SMS) messages on your device and send messages to other phone numbers. Standard carrier rates may apply. This service requires the IFTTT app for Android.
openHAB - a vendor and technology agnostic open source automation software for your home.