0x Instant is an embeddable widget any developer can include in their app or website to offer their users non-custodial Ethereum token purchases. Basically, it lets you purchase ERC20 and ERC721 using 0x liquidity from any website using your Ethereum wallet of choice. See it in action on Aragon to buy ANT.
I built Instant with a small team of talented engineers and designers at 0x. It has been included in many decentralized applications, and processed thousands of ETH worth of Ethereum token purchases. It is also an extremely popular at hackathons, as it is the easiest way to get up and running with crypto purchasing.