The choice of development platform significantly affects the cost of car wash app development. Choosing between cross-platform, iOS or Android development is crucial in determining the funding required. It is more economical to choose to support one platform instead of several. The cost of car wash app development can vary between $30,000 and $60,000 depending on the complexity of the application, further affected by factors such as the design of the app, coding process, location of the car wash app development company, etc.