Pokémon Go becomes global craze as game overtakes Twitter for US users

Nintendo's share price soars but there have been safety fears over players visiting secluded locations late at night

An app that began as an April Fools joke has become a worldwide phenomenon, taking gamers out of the living room and on to the streets as they compete to capture, train and battle Poki(C)mon characters using their mobile phones.

In just seven days since the game was released in the US, Australia and New Zealand, Poki(C)mon Go has now almost certainly exceeded Twitter's 65 million American users, and the game's servers have repeatedly crashed under the strain of its popularity.