This app is called Biashara book. This is my secret sauce. I used it to plan, strategize, monitor and run my business smoothly. As you can see it has POS, inventory,sales/expenses , invoices, suppliers, customers , receipts.

With this is easy for me to know a)Total sales. b) Total stock c)Total expenses D) gross profits

You need to have a well set plan and strategies to succeed in your business.