With it, you can:
To get started, visit the project page and follow the instructions there. Although you'll need to use a command prompt with this, I tried really hard to make it understandable for people who haven't used it before. Please let me know if there are parts that are confusing about the instructions!
Keep in mind that this is the first public release, so there may be bugs lurking here. If you do run into problems, please add a bug report to the project page. There's also room to grow here, too. I can see adding a Twine 1 -> Twine 2 converter to this project, and also adding a mobile app builder with PhoneGap/Cordova in the future.