Twisted Threads is an online tabletweaving design application at twistedthreads.org/. It has a special interface to help design doubleturn doubleface designs. This video shows how you can start from a square grid chart, for example a knitting or cross stitch start, and easily create a tablet weaving pattern with Twisted Threads.
The patterns designed on the video are public, they are at twistedthreads.org/pattern/KL... (red cornflower) and twistedthreads.org/pattern/sw... (blue cornflowers). Note that in Twisted Threads you can only view patterns other users design, not change them. To create your own patterns, you must register as a Twisted Threads user and log in before the "New Pattern" button is available to you.