Pdf reading app for iPhone

Do you know about a good pdf reading app for iPhone that can underline and highlight text, with colours, while in Reading mode? I want to use it as an eBook reader, and would like to highlight and colour text while reading. I’m also looking for a good .ePub app.

Have you tried Adobe Acrobat reader? I see there is a separate PDF Editor/Reader which I haven’t tried. Ads of course but this should be the most professional way to read things. If there are reasons you don’t like this one let us know and maybe someone has something better.