According to a new E-Marketer report, Instagram now has more American based smartphone users than Twitter. Here are the specifics: Instagram has 35 million US mobile users, while Twitter has only 30.8 million. But for all users – which includes desktop users – Twitter still claims 40 million more users than Instagram, with 240 million total active users worldwide each month as compared to Instagram’s 200 million. The news comes on the heels of Twitter’s attempts to increase mobile engagement with multiple photo uploads and image tagging to, at least by the looks of it, compete with Instagram. Clearly both are viable platforms based on the numbers, but for the moment Instagram is creeping out in front, from a mobile point of view.