ZK-rollups use ZKPs by combining a large number of Layer 2 transactions (off-chain) into one transaction that then gets mined on the Ethereum mainnet. Instead of mining 100s of transactions individually, they can be rolled up into a single transaction.
StarkTweet, a fully on-chain, decentralized microblogging platform where users can share tweets, media, likes, and manage their identity, all via cryptographic verification and smart contracts. Built with Cairo 1.0, StarkNet.js, and Pinata/IPFS, StarkTweet combines the best of decentralized infrastructure with the social expressiveness of Web2.