So I got started immediately with integrating it into TweetSaver. Unfortunately, I ran into a show stopper pretty quick.
When passing a signup event, they require you to send a unique username. This was a major bummer since for the free level of my app, users are not required to give an email address and in general emails may not be unique to a user in the system. This essentially renders sunnytrail unusable for me.
The best part though is that co-founder Octav is always in the live chat on the site, so I explained my situation and he said they would take a look to see if there is a better solution. I'm anxious to see if they can make some changes that will allow me to use their service!