I've tried many Chinese-learning websites and applications. Pandarow is just the BEST of them. The courses (only available on their app) are so detailed, very friendly for beginners. I love the Q&A forum of Pandarow, the native speakers are so warm and friendly, just leave your questions there and you will get a answer very quickly!
REAL free and REAL no-ads. If you really want to learn Chinese as well as make friends with learners from all over the world, this is the app you are looking for.