Earning from app

Salam. I have installed an app that collects my surfing data (like facebook) and sends it to Tobiipro, a marketing (eye tracking) research company to study. They study my data on many aspects. One of them is which website I visit, which ADS appear on screen. All I need to do is to use my phone as usual and the app runs in the background. They give me 15$ every other month as a gift. Is the money halal?

Note: I used to use my phone in the same way before installing the app. The app doesn’t show me any ads, nor do I show ads to others. What happens is that they check my visiting website and check those ads which are on that website. I am not in control of those ads, neither are they. Even if I do not use this particular app that collects my data those ads will appear on my screen because I use google, youtube, facebook etc.