I love the customization features in the Settings. You can choose the sentence type(s) to address, and if you would like pronouns or nouns. You can decide when to give rewards, levels of cueing, etc.
For pre and post testing, you can choose the "Watch and Say" activity in the settings. Here, you see an animation, there is a cue, "What is happening?," then a child records his/her sentence. There are three dots below the animation to help cue the parts of the sentence if needed.
The next activity is "Build a Sentence." In this activity, a child can choose the subject, verb, and preposition or object of the sentence.
When the parts are chosen, an animation of the sentence is shown, and then the child records the sentence.
I highly recommend this app because it address sentence formulation goals, pronouns and verb tenses, while being highly engaging and motivating for kids ages 2-5 (or for lower functioing early elementary students). It is currently on sale for $9.99 (through October 31), but is regularly priced at $15.99. Here is a link to check it out! http://www.appymall.com/apps/fun-with-verbs-sentences-hd