Blockchain startup Blockstack says it raised $52.8 million in its ICO, finalized Friday. The company is building a sort of parallel to the internet that users access via the Blockstack browser and that features a wide variety of apps. The Blockstack ecosystem promises to benefit both users and app makers. It gives users control over their own data via a personal API. Meanwhile, it allows developers to launch apps without having to host user data or worry about related storage costs and data privacy.