Sentence Builder is an excellent iOS app designed to help students ages 4-7 learn about: grammar, sentence structure, pronunciation, and more. This is done by dragging and dropping words around to build sentences. Also, a user can upload their own pics and include them in a sentence and even record their own voices. Sentence Builder is ideal for self paced learning and has two different levels to choose from.
I highly recommend checking out Sentence Builder by clicking here!!!