I want to develop android application smilar like step set go in play store. also want to add some more features into it. app must be smooth and secure no hack or cheat must apply to the app. App may use google fit data. My app must count the person walking steps per day and collect daily records and daily maximum records can covert into the coins which can be use in my own store in application. App must have the store where other ads and post can be done by the admin.
Also my app will have coupon code facility where anyone can use collected step coins to buy coupon for different things or can convert coins to coupon.