Q4L is one of the best app I got here.
I tested the app before buying, and I submitted some question (using my another account "equipe@k01.com.br"), and they were quickly answered.

In the tests I could see the features it offers, and the support was the best part.
The app is easy, intuitive and generates amazing - and responsive - quizzes for lead capture, or using when you interact with it.
You need to have it!
Humberto - Brazil