Yes, we can help you with the required modification in your app even after it has been launched. We at Blue Whale Apps highly recommend developing an MVP (minimum viable product) version with the simplest yet crucial features first. This can help you test the market approach and get more information regarding further changes to be made in the app.
You can then decide to update your app version or work on the next sprint based on the agreed project quote or provide fresh requirements to develop new features.