The Monkey app, which let users send and receive money through their smartphones, was shut down on Wednesday after the company could not keep up with the demand for its services. The app had been downloaded more than 10 million times since it was launched in 2014. Monkey CEO David Marcus said in a statement that the company had been working hard to scale up its operations but “we couldn’t keep up with the demand.” Marcus added that he was “heartbroken” to have to shut down the service but that it was necessary in order to focus on other projects. Monkey’s closure comes as a surprise given that it was one of the most popular mobile money apps available. Some have speculated that its closure may be related to increased regulation of mobile payments, while others say that it may have been due to competition from newer and more innovative payment platforms. ..