Postearn.co is a blockchain-based social media application focused on the 'post to earn' model, representing an advanced project in this space. The BETA version has been released allowing users to sign up now at www.postearn.co. Similar projects include Pohsten, which aims to create a real-world use social platform with locked liquidity and team tokens. WriteChain is another related project focused on 'write to earn', rewarding users for content creation.