Https://surveys.google.com/google-opinion-rewards/ This will be your most legit option. Source: 6 months ago

They have one already you only get play store credit though. Source: 12 months ago

Since people are asking: This one? https://surveys.google.com/google-opinion-rewards/ (links to Apple and Google downloads). Source: about 1 year ago

Little trick I figured out a while ago, I answer Google Opinion Rewards every time I move around my city, which pays 10 to 75 cent on my google play balance and then can be used for youtube subscription. I get 5$ a month easy in my small City, with barely a work commute every now and then plus groceries. Easiest way to support your favorite cult. Source: about 1 year ago

This is a super oblique way to do it, but I've gotten a couple for free over the years by doing Google Opinion Rewards surveys and buying them off the Google Play store with the credits. Source: over 1 year ago

Their largest business is largely mobile ads in mobile games, as I understand it, and has been for a while. As a business, they haven't really competed all that directly with Unreal for AA/AAA games. If you like ads in mobile games, root away! > https://unity.com/products/unity-ads. - Source: Hacker News / about 1 year ago

The SLOWLY app mobile version packages include libraries to connect and use different ad services companies. With this version, I see a lot of ads provided by Unity Ads - which is popular both in iOS and Android markets. Source: over 2 years ago