title_body: Are there any free online conlang creation tools?
upvoted_answer: There are some syntax "toys" online, eg http://www.zompist.com/gtg.html. This will help you write a (formal) grammar of your language, but you will need a good understanding of Generative Linguistics to use that.
  
  Otherwise, what else do you need instead of pen and paper? Maybe a spreadsheet to enter vocabulary? There are so many choices to be made on so many levels that it is not really possible to automate much of it. It's not as if you would enter a few characteristics into a form, press a button, and out comes a conlang :)