The time and cost for developing an on-demand beauty app can significantly vary depending on the complexity and features of the app. However, based on our previous projects like Geneium and GoodSkin, a basic version of an on-demand beauty app can take around 3 to 6 months and cost upwards of $150,000. The timeline and cost can increase with the addition of complex features, integrations, and if the app requires compliance with certain standards.