Prices as of August 2016 are listed here to help parents identify specific apps if they choose to buy them for home iPads or iPhones. These are exactly how the apps are listed on iTunes:

Starfall Learn to Read $2.99 Pre-K-1 includes 15 mini books and activities, movies, songs in a playful, colorful, cartoony setting.

Bob Books #1 Reading Magic $3.99 same art as the Bob Books which have been out for years. Early phonics, very simple art, K-1.

Reading Raven $3.99  Pre-K-1, Award winning, word tracing, kids record their reading, more game than using repetition, repetition, repetition for simplest letter and word lessons

Froggy Phonics $0.99 Pre-K-2, This is based on a board game drilling sounds then how sounds make words. 

Fluency Level 1 $1.99 Grade 1-2 timed recorded reading aloud, playback to teach how kids can use their voices to convey context and decipher meaning. Goes beyond phonics by screens showing what to read with color coding to help with emphasis and style.

Minimod Reading for Details Lite
 $3.99 Grades 2-6 offers a selection of non-fiction then asks a few questions to build comprehension. Good practice for standardized tests and thinking beyond words to grasp more complex ideas.

Opposite Ocean $0.99 Grade-2-6 video game with emphasis on score keeping. Points are accumulated by filling in the blank in a simple sentence with the opposite of what is first written. Multiple choice with increasingly higher level vocabulary.

Sentence Builder App $5.99 Grade 1-2 With a display of a picture and word surrounding the picture, students drag and drop the words into position to make a logical sentence.

2nd Grade Non-Fiction Reading Comprehension

3rd Grade Non-Fiction Reading Comprehension $2.99 These are read-a-selection-answer-questions style demonstrating how non-fiction comprehension requires a different thought process than fiction for full benefit. (These are longer reading selections than App listed below.)

Reading Comprehension Grades 2-3 $1.99 See above. This app has 91 non-fiction shorter animal related selections with only one question per selection. Photos make this one more attractive than above. Multiple levels of selections within the Grade 2-3 range.