It seems the author removed the previous post, so I'll share it here again. Basically, hundreds of accounts were created solely to farm coins.
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Free coins were removed due to abuse. We hope to bring them back in the future, but unfortunately, we haven’t had much luck with the ad provider.
I'm not sure if we'll be able bring it back. If we are able to, it will likely be very limited, or we'll need to find another provider due to the massive amount of abuse. We distributed over half a million coins in the last 30 days alone. We do plan to introduce more ways for users to earn coins after the new version is released.