What comes after One? Well, the HTC One (M8), of course! If we haven’t made our feelings clear, “One” is a terrible name. But we won’t go into that again, the HTC One was a promising phone that did things its own way. The M8 is the sequel to that and introduced a camera feature that is still very popular today. Or should we say “common” since popular implies that people like it. We often mention the HTC EVO 3D (from 2011) as one of the first dual camera phones (along with the LG Optimus 3D). However, that wasn’t very useful since 3D was a gimmick that only seems to work in movie theaters...
Source: https://www.gsmarena.com/flashback_the_htc_one_m8_had_two_cameras_and_two_oses-news-51233.php