Hello English: Learn English is a free Educational App, It's featured as "GOOGLE'S BEST OF 2016 APPS" and "MOST INNOVATIVE APP OF 2016" By IAMAI.
App provides more than 400 interactive lessons with English, grammar topics, vocabulary and more. All lessons work offline as well.
On reading, translation, spellings, grammar, vocabulary. With immediate results and grammar tips.
The app is available in more than 10 languages.