I have been using Windows Phone smartphone with 8.1 version on board and 512 MB of RAM. In my opinion, the mos frustrating thing was crashing web browser, i.e. Internet Explorer. Therefore, I prefer to use Opera Mini and this is my favourite web browsing application for all mobile devices. Mainly thanks to great data saving feature.

Unfortunately, I have very sad news for all people who use smartphones with Windows operating system. Windows Phone version of Opera browser will not get any new feature in the near future. They have tried to port iOS version using Microsoft’s bridge tools, but it turned out that it is not so easy.

In short: no major updates are planned for the next few months. This is,
of course, not set in stone, and we're hoping to review the platform
later this year. But, right now, the small team who were working on the
Windows Phone app are now dedicating their time to our other apps on iOS
or Android.

Having said that, we will continue to make sure the browser on Windows
Phone is still secure to use. The developers are also keeping an eye
on bugs to fix major annoyances as they can (so keep your bug reports
coming in!).

There is a hope, because this decision will be reviewed later this year. Also, Opera promised to provide all security and maintenance fixes for Windows Phone version.