I am scoping a project I would like to build as a web app. To get an idea of how much work was involved in creating one I made a quick test app and published it here on the Apple App Store. Given my skill set the design work was a small part of the job (12%), CSS & JS was three times more (38%) and the rest of my time was spent on new stuff to do with getting the app to run on an iPhone (60%). I can probably halve that on my next project but it was a lot harder than I expected.
It’s a fun app, you can make lists like this 😀