Need a developer for native Android and iOS app for 7 bugs

A brief description of the bugs are as below:

iOS issues:
1. Item that do not have a list of add-ons to select from, are not added to the cart. Although a message will display that item has been added to cart. This is on both US and UAE.
2. When adding tips to driver, the amount is not reflected to the total.
Android issues:
1. When clicking the place order, nothing happens. Like iOS, if no address selected, it should popup a message to select an address and same for if payment is missing.
Android & iOS enhancement:
1. Add ‘x’ to the add payment section
2. Remove the ‘Referral code’ from the profile page and make sure to fit all in same window.
3. Remove the amount from the ‘Place Order’. Make smaller the button. Increase the ‘Pay Using’ field. Make Place Order 50% of the page width and the ‘Pay Using’ button to 50% of the page width.
4. Make the maximum number of characters in CVV to 4.