Flappy Bird
Flappy Bird is a free game that has reached top place in Apple and Google stores.Google Play

Flappy Bird, the relatively unknown bird-flying game from Vietnam-based developer Dong Nguyen is highly addictive, and has now gone viral.

This free game, which was released in May 2013, has currently climbed to the number one spot in both Apple and Google's stores.

The reason for the game finding instant success is said to be the overnight popularity it got from waves of funny tweets, YouTube videos and reviews on both iTunes and Google, which all helped in boosting the image of the game, reported Mashable.

"The popularity could be my luck," said Nguyen, the indie developer, during an interview with Chocolate Lab Apps. He stated that the main reason for its success is due to the game being simple, and added that most of the West-made games are unnecessarily complex.

The popularity of Flappy Bird has also made people take note of Nguyen's two other games - Super Ball Juggling and Shuriken Block - which have reportedly gained fourth and ninth places, respectively.

The developer has promised that a Windows Phone 8 version of Flappy Bird will be out in a couple of weeks.

The chief objective of the game is to allow the bird to fly, by tapping the screen. The player needs to make sure the bird does not hit pipes and other obstacles. Everytime the player manages to pass a pipe, he gains a point.

Flappy Bird has been criticised by many but still remains a popular title, as some players find it extremely difficult.

The graphics of the game is akin to Super Mario and has a very basic mechanics. However, the game has advertisements, which is how it earns its revenue. It is said that the game earns on average $50,000 per day from in-app ads, The Verge reported.