The demo and beta experiences are just a taste of the final app. The demo only includes a couple of pronunciation training exercises and 8 words worth of content, and the first version of the beta includes around half of our pronunciation training exercises for Spanish and 47 words worth of content.
The final app will have much, much more: 625 base words with 1875 sentences, around 35-55 pronunciation lessons per language, an ever-expanding community database of sentences, and the ability to add your own content.
If you're playing with the beta and you'd like to explore some of the options you missed (because you indicated you were a beginner in Spanish, or you marked all the words as 'known'), then uninstall the beta app, reinstall it from your Hockeyapp invite email, and then try the beta all over again! (Or wait until we update the beta, at which point you'll get a lot more content to play with!)