Second grade students can study 40 different spelling lists and learn over 400 spelling words through a series of fun spelling activities.
Flipidee Animals lets children explore and build a variety of animals while learning their names and practicing their spelling skills. This is a great app for young children!
Star Speller, a spelling app for kids in kindergarten through second grade, has two games and a flashcard mode. Reasonably priced considering the features and content it offers.