Soundboard App Developer Full Stack

We are looking for an application developer that can help us develop an application like the following:
https://bit.ly/4i0rL7P
https://bit.ly/3Z6zJU6

The application should be IOS and web friendly to begin with the ability to offer Android at a later point. We would like to be able to provide the sound effects and the background music that will be used for this application. Looking for this to be ad supported with a subscription offering that would be ad free and open up more access to more sounds.

Please make sure to provide a quote of what this application would cost, timeframe and also examples of work you have done before that is similar or work to show what you have been able to do.