Apple has made a lot of new regulations about different app installations, downloads, and payment systems. They want a share on in-app payments, in short, app developers and companies would share their profit to Apple - a practice that they didn't do before. Now, the only way to avoid this is to let users use their app without letting them download it. Hence, these are apps that you could use like a regular app, but you don't really need to download them anymore.
There are pros and cons of course. One of the pros is that your memory isn't really affected with these kinds of apps since they wouldn't eat your memory up. On the other hand, if you own a high-memory device, memory isn't much of a problem, is it? Meanwhile, one of the consequence is that you can't access these apps automatically as compared to other apps installed on your iPad. Most especially, you can't do anything with them if you don't have an internet connection.
Apps That Do Not Require Installation
This is because these apps are based online, which means the only way to access them is through your browser. Two of these apps are the Amazon Cloud Reader - which lets you download and read Amazon eBooks, without the need to download the Kindle app; and the Vudu web app that lets you stream videos according to your subscription.
See how tricky both of these apps could get? They avoid all the extra fees that Apple imposes, while at the same time, continues to provide their service to their users. Only time will tell until most of the apps do the same, but then again, what are apps for when all the apps go online-based? Would we say bye-bye to icons already? Is this the real vision of Apple? Or are they really just maximizing their profit as much as they could? Who knows?