The app is a new industry. It creates demand for new job.
Transport app is yet to be profitable. It will not be able to support even 1 programmer. But app demand is strong in bank, MNC, government, media. Each project would requires the above profession.
App has users in the range of 10 million. Every one uses an app. Website is only limited to a PC in the house. Or limited to being at the office. App is used any time any where by every one.
Advertisement used to be you come to a place, you see it. Then it becomes, you read the paper in the morning, you see.
And become you use the web, you see it.
Now it becomes, you use your phone, you see it.