Just go log in with a google account here:
sUTL Studio should be considered alpha software at the moment. That said, I use it for all my sUTL work, and it powers all the examples on this site, so expect it to keep working.
Love sUTL and want to help out? I've built sUTL Studio because an online tool is necessary, but I really wish I didn't have to maintain it. If you'd like to help please let me know!