1. Write an application for Mobile Store where the user can view the available mobile phones in the store according to his/her preference. Store the mobile phone objects having attributes model number, OS, and Price. User should be allowed to filter the phones on the basis of those features. If user selects the model number, then ask to enter the model number and then display all the details of the phone with the given model number. If user selects OD then ask to choose the OS( Android/Windows/IOS) and display all the mobiles with that OS. If the user selects Price then ask to enter the minimum and maximum amount and display all the mobiles which can be bought with that amount. Now ask the user to select the mobile and display the details and bill. 2. Write an application for Cellular Company which provides different post paid plans for Calling/SMS. Ask the user to select the service provider and Display the menu to select the plan/pay bill. If user wants to selec...