You are allowed to fork any dApp from any other chain. As long as the code is open sourced (which is the case with almost all dApps) you can literally use the same logic to BUIDL your own version on Reef Chain.

• Reef Name Service —> You must have seen people using .eth, .lens, .sol etc in their twitter username. Well how about having a .rns the Reef native Name Service. I’m sure a good bunch of Reef Community will love it. It will have some really good utility in the future as well.
• DAO infrastructure and tooling —> Reef Chain doesn’t have a fully fledged DAO yet, if you could create one that’s useful for the community then you’d be the first DAO on Reef Chain. How cool is that ? 😍 The best idea though would be to have a DAO infrastructure using which anyone could create a DAO on Reef Chain Resource —> https://buildspace.so/builds/dao
• DEX on Reef chain —> With the recent Centralised Exchange fiasco, the trust in Decentralised Exchanges (DEXs) is gonna increase. Since Reef has super low gas fees, it’d be a good idea to have a fully functioning DEX right now
• Governance Platform —> Reef community is ever growing and we definitely want our stakeholders (The community) to have a platform where they can vote on different proposals, have their own proposals, have discussion etc. The basic version of the platform would be having the ability to vote on different proposals via token and NFT gating. You could easily find the contract code for this :D
• Staking platform —> You could build a staking platform on Reef Chain (Give an example)
• Yield Farming —> Build a yield farming platform on Reef Chain (Give an example)
• IDO Launchpad —> Build a DeFi Launchpad on Reef Chain
• Any DeFi product
• NFT Marketplace
• NFT Liquidity Pools —> Create NFT liquidity pools like Sudoswap https://sudoswap.xyz/#/
• Social Media Platform Infra on Reef Chain —> How about you create a cool social media platform that utilises the Reef Blockchain infra? You can get creative here. We have got a super awesome and easy to use UI Kit for all your platform aesthetics
• Cool Game on Reef Chain —> Reef Chain is optimised for Gaming and the community is really interested in having a some really cool games Built on Reef Chain itself. So if you’re into gaming then its a good idea to have a game Built on Reef and you’ll get some users by default from the Reef Community
• Mobile game —> We have a flutter mobile app integration that you can use to create a really cool mobile game. Reference —> ‣
• Metaverse —> Metaverse is a really cool thing right ? How about a Reef themed metaverse ? This would be one of the coolest things on Reef Chain. We already have a native NFT Marketplace on Reef https://sqwid.app/ which you can leverage in some way in the -metaverse. You can make a sea metaverse based on Reef theme
• Any other cool dApp…

More Places you can find a dApp idea at