American Sign Language??
I'm wondering if American Sign Language could be an option. I am already fluent, but I know so many people who could use this type of program to learn quickly. I work with many hearing people that are trying to learn sign but could use a tool as simple as this to learn easier.
If you look at most classroom signing workbooks, it would be very similar to those. They use arrows and other symbols to indicate a direction. Take "week" for example. (Here, I'm using Bill Vicars ASL LifePrint stuff to illustrate my point.) https://www.lifeprint.com/asl101/images-signs/week.gif The arrow along the non-dominant hand indicates that the dominant hand (the one making the pointer finger) slides across the hand from the base of the palm to the fingers.
As for the "speaking" part of the language, I don't know. Maybe a video? My ASL teacher had us posting videos to YouTube all the time so she could see our progress one on one without anyone else in the way.