Cryptocurrency wallet iOS App

looking for a developer to build an iOS cryptocurrency wallet app (and later convert to android) the app functions as an escrow wallet, meaning: - buyer transfers crypto from their own wallet into the app escrow wallet (this is the "deposit") - seller can check that cryptocurrency has been received (then seller can send the product by mail) - when buyer receives product, all parties can confirm release of crypto payment into seperate wallets (seller will nominate different wallet numbers and how many wallets to receive the deposit and % to receive from deposit into each wallet) diagram attached features to include: - escrow wallet has crypto exchange function to convert to other currency (fiat or crypto) - security feature in escrow wallet means, no money can leave escrow wallet unless all people agree where money is transferred (seller can nominate action that all people vote yes/no ) - wallet 1,2,3 are additional wallets in the app that the seller can either create and or they can nominate a seperate wallet public address, they can also add more than 3 wallets - seller determines % from escrow wallet that goes into each 3 wallets - all wallets can see deposit in escrow wallet but only seller can suggest a transfer this does not need to be built from scratch, i know there are other crypto wallets and exchanges that allow you to use their API to do these functions so you can create this app through their API