The primary source of revenue for mobile app companies are subscription paid by the users on an annual or monthly basis. Advertising (selling ad space to other companies on their app) is another significant revenue sources.
The key expenses for mobile app companies are the costs to advertise and generate users. These expenses are often in the form of targeted social media advertising or online targeted marketing. Some major mobile app companies pay to have their mobile apps advertised on television commercials or music streaming platforms. Another major expense for app companies are office space, employee salaries and technology licensing fees.