SHP Verbos app for iPhone and iPad
This app is useful for students studying Spanish at the high school level. It contains a list of all the verbs used in the Spanish 1, Spanish 2, and Spanish 3 classes at Sacred Heart Preparatory, a high school in Atherton, California. For each verb, a student can look up the definition and the conjugations in various tenses. The list of verbs is also fully searchable.
There are lots of Spanish language reference apps out there, but this one does exactly what a high school Spanish student wants.