Why is One Gallery discontinued?

Although HTC wanted to continue supporting One Gallery, some of HTC's partners are discontinuing their support which in turn makes One Gallery less compelling. You may want to consider using other services. For example, use Google Photos to view photos and videos you've backed up from your phone to Google Drive automatically as well as media files you've manually uploaded. Google Photos and Google+ also feature auto-categorization for photos stored in your cloud storage through image recognition.