Welcome to The Bio Dude!
Java Moss is a plant that is super hard to kill. It can handle the abuse of a rookie or can thrive in the tank of a professional. It's so hardy that you can keep it out of the water for a good long time and not worry about it dying. It's actually a moss, so not to worry, it can handle no water.
Java moss works great in both the low tech and high tech tank. I would even go as far as to say that it is better to be kept in a low tech tank over a high tech.
Care Scale of 1-10: ( 1- it can grow in your toilet- 10 being nearly impossible) JAVA MOSS IS A 1!