for example, the price of 1 kilogram sugar is 25 Rupees, and a customers comes and say: hey, give me sugar of 17 Rupees. and you do not have a digital scale in your tiny store what would you do ?

don't worry, this app is for you !

this app says Rupees (pakistani currency unit) but, it works for every currency unit... USD, MYR, EURO, IND, and all !...

NOTE: This app does not work like the physical digital scale, you keep something on it and it calculates the weight, rather it has the software of those scales. Means, it only calculates and you have to weigh it yourself on a traditional scale.
SO, please do not give bad reviews.