Web apps are completely customizable websites that can do nearly anything. They save and load data, allowing for a user experience with personalized content. Online stores that require buying & selling capabilities, e-commerce, user forums, or any site that requires sign-ups and log-ins require a web app.
Software innovation, like almost every other kind of innovation, requires the ability to collaborate and share ideas with other people, and to sit down and talk with customers and get their feedback and understand their needs.
Store windows are like landing pages on the website.
Information technology and business are becoming inextricably interwoven. I don't think anybody can talk meaningfully about one without the talking about the other.
If you can dream it, you can do it... The way to get started is to quit talking and begin doing.