wobr - I don't know since there platforms can provide you with specilists whose working process can differ in time, and I don't even know how long does it take to develop an app.

ho - It's really complex friend, it depends on what you want to make, but if you want to know more about what does it take to develop an app check https://content.techgig.com/how-long-does-it-take-to-develop-an-app-overview-of-the-main-stages/articleshow/76767150.cms , check the site and let's hope it helps you clear some ideas!