Make me a distributable crypto mining application

Hello, We are a website that offers a service where users can earn an ingame currency of a popular game called ROBLOX by completing surveys and downloading apps on our website. We want to add another earning option on our website that lets our users download a miner app, which lets them mine cryptocurrencies on their PCs by using their graphics card. For each amount of money the user mines for us we would reward them with a respective amount of the ingame currency in our database through the use of APIs. Once a user downloads the app, they would authenticate using our websites APIs connected to our database, and after which they can start mining and earning currency to their account. The app would look a lot like this one offered by a competitor of ours [login to view URL] you can visit the site and see what it looks like. We only want you to develop the application, we can provide any APIs needed for authentication and third party services that may be required to make this program function.