Cal.com - Cal.com (formerly Calendso) is the open source Calendly alternative.
Fondu - Open source free ICO smart-contract builder
Dune Analytics - 675 million+ members | Manage your professional identity. Build and engage with your professional network. Access knowledge, insights and opportunities.
thirdweb - thirdweb is an ecosystem of SDKs, dev tools, and dashboards that help teams build and manage web3 apps. Deploy custom or pre-built contracts to ETH, MATIC, AVAX, & more.
Unidata - We all know that it is not that easy for web3 developers(especially for front-end) to access and present Web3 data due to the infrastructure design of blockchains.
Cues.sg - Cues is a website that generates code for your own smart contracts and Web 3.0 apps, in a simple 3 step process.