Build an app

I want to create an app similar to Zikanalytics, wich will allow me to find the best new posted selling products, the amount sold, and the total revenue of any single product. and this in different time frames, such as a month, a year, a weak or a day. how to work: 1-i must put different eBay sellers username as a list. 2- i can pick the shipping location " country". 2- The result must show the new posted item that was sold, filtred by the total revenu or newest or number of item sold. 3- Ability to save data for later reference.