Dong Nguyen, the creater of Flappy Bird thinks different about this topic - this is also the reason why he took the game down for the app stores:
'"Flappy Bird was designed to play in a few minutes when you are relaxed," the developer said "But it happened to become an addictive product. I think it has become a problem. To solve that problem, it’s best to take down Flappy Bird. It’s gone forever."'
> http://compethics.samething.net/2014/02/20/flappy-bird-and-u...
At least it is not on Google Play anymore:
> https://play.google.com/store/search?q=Flappy+bird&c=apps
and by
> https://en.wikipedia.org/w/index.php?title=Flappy_Bird&oldid...
it is also not on Apple's app store anymore. What happened is "As Nguyen had promised, August 2014 saw a revised version of Flappy Bird, called Flappy Birds Family, released exclusively through the Amazon Appstore for the Amazon Fire TV platform."