Whoa. If you want content quickly many apps will offer it in widgets. Many will show you notifications with ability to interact with them without even opening the app.
There is nothing instant about websites.
My point was: There's no problem with casually checking out a website. But I'm probably not gonna install an app unless I'm pretty sure it offers me some value. Not rational? Possibly :)
Open browser, create new tab or focus url, enter url
Open app store, search for app name, click on the one that seems correct, read reviews, click install, wait for installation to finish, open new app.
This of course is only valid for the trying a new application or website which hypothetically is 0.001% of your usage of an app.