“Over the past few years, mobile web usage has considerably increased to the point that web developers and designers can no longer afford to ignore it. In wealthy countries, the shift is being fueled by faster mobile broadband connections and cheaper data service. However, a large increase has also been seen in developing nations where people have skipped over buying PCs and gone straight to mobile.
Unfortunately, the mobile arena introduces a layer of complexity that can be difficult for developers to accommodate. Mobile development is more than cross-browser, it should be cross-platform. The vast number of mobile devices makes thorough testing a practical impossibility, leaving developers nostalgic for the days when they only had to support legacy browsers.
In addition to supporting different platforms, each device may use any number of mobile web browsers. For instance, an Android user could access your site using the native Android browser, or could have also installed Opera Mini or Firefox Mobile. It’s fine as long as the smartphone uses a progressive web browser (and it’s safe to say that most browsers are progressive nowadays), but it doesn’t have to.”