Android wallet for own cryptocurrency

We need our own wallet made for Android, the wallet should be able to buy, sell and transfer our token. The first feature of the wallet should be to connect to your own wallet, using the metamask and trust wallet api. After connecting the app should be able to consult the amount of tokens the client has and the value of it in $.

In the same screen, the client should be able to buy more, using the paypal api, stripe and using other stablecoins as BNB (since they have logged in with their tw or metamask, they will be able to see what stablecoins they have). Buys must be automatic, meaning the buyer will receive x tokens sent from our wallet to their wallet aftet the payment is received, and the opposite when somebody sells the tokens, he receives back his money, and we receive back our tokens.

The main feature is to use only for our own token, but in the future we might be interested in implementing the same thing for other tokens, this means that if we want to collaborate with another tokens, this will be added to our own exchange and costumers have to be able to buy them using the same methods.