You can download this app both in android and IOS. It is the best app for IELTS preparation and I personally use this app.
IELTS test pro
With IELTS® Test Pro, you can study for FREE with our questions, practice tests, flashcards, and score reports with detailed analytics.
IELTS Skills
Free provides samples that content each IELTS Skills app including Reading, listening, writing and Speaking skills all represented in the sample contents and tips or tricks to solve test lesson.
Word Power
An App to educate yourself with ease, enhance your vocabulary while on the go. We provide you with volumes of vocabulary building at your finger tips.
BBC Learning
The official BBC Learning English app brings together all of your favourite lessons and presenters in one fantastic, simple-to-use package