The Educational App Store has rated both DoodleEnglish and DoodleSpell 5 out of 5 stars.  

“There is a broad range of English grammar knowledge taught and tested in DoodleEnglish. The different types of words such as conjunctions, verbs, and nouns are covered as are types of words used for artistic or creative effect, such as alliteration and rhyming. Tenses, punctuation, clauses and other topics round out this app into a comprehensive teaching and revision guide for developing strong English skills.”