Why the app was not successful?
There was several reasons that app could not draw many users. Google wave was one of them who failed their marketing. Google wave was to make it easier for user to group in mail. It meant to serve the good purpose. But, people did not really know what the application would bring to them.
The one of reasons is that Google Wave did not have an easy interface. Too many options and icons are cluttured in a page. Its complicated interface did not draw user.
Hailo was one of apps that connected passengers and taxi drivers. Hailo was launched in London and later was launched in NYC. The difference in London was that taxi drivers were more trained and professional as opposed to NYC where those did not have smartphones. So, the different culture in NYC is one of reasons that failed Hailo. To add another issue to it, Uber started service way cheaper.