I developed a qBittorrent controller for Android. It has many of the features provided by the web UI in a native Android application.It's available at Google Play, and It's open source so the code it's available at GitHub and the the latest apk can be downloaded here
Screenshoots (UPDATE: 02/08/2015)
Phone's view




Tablet's view


qBittorrent Controller Pro
There is also a paid version called qBittorrent Controller Pro, available on Google Play . This version includes a nicer UI, the latest features and fixes of qBittorrent Controller for Android and some features only available on qBittorrent Controller Pro.
Screenshoots




qBittorrent Controller (free) vs. qBittorrent Controller Pro
Both versions have the same functions for handling qBittorrent servers, but qBittorrent Controller Pro is the paid version which includes a nicer UI, and the latest features and fixes of qBittorrent Controller for Android.
By the way, both versions are published at github, but the apk file for the Pro version will be only available on Google Play.
Enjoy it!