It’s not a substitute for learning how to write characters by hand. I worked as a substitute teacher yesterday and saw a Chinese boy and a Korean girl teaching each other their respective languages. I joined in, of course, and showed them how to write them in the native script (they were both using roman letters). I realized, after a few abortive attempts, that I was unable to write ~95% of the characters I knew! I had no problem reading them (the Chinese boy knew how to write them); I just didn’t have the muscle memory encoded in my hands. Just a word of warning.