You have to subscribe before you can create your own texts, right?
If you subscribe (or if you have a student login because your school has a Premium or Group subscription) you can take full advantage of the site's interactivity by using texts that you paste in there and then. Or you can save texts / resources to local storage, to access them later on the same device. You can save 100s of resources in local storage.
You need to have a subscription (Premium or Group) if you want to save something to share with others via a hyperlink or embed code, or (Basic) to access your own saved resources on a different device.
If you have a Premium or Group subscription you can also get your students to log in using the student login and share text with them in other formats (word doc or txt file) which they can then copy and paste into textivate and have access to all the activities. The student log-in also allows students to play around with their own text and submit scores based on textivate sequences.