Real Estate Evaluation Subscription App

Create a subscription-based app for both Apple Store and Google Store and also get those apps uploaded to those stores. I have created an app using Base44 AI which I am happy with as far as the appearance and function. However, they don't have to tools to enable the subscription-based function. The app is very basic, I created an Excel worksheet that performs simple functions and the app is to present that data, along with ability of the user to input background information that the worksheet utilizes to make the calculations. It's essentially a tool that gives real estate beginners the ability to input variable info in order to determine if the property is a good deal. The app needs to be visually professional, easy to read/display, and also include a pdf download capability of the information.