Features

Watch live TV in Browser (VLC Browser Plugin required)
EPG access (Electronic program guide)
Scheduled Recording of TV program to QNAP filesystem. Writes MPEG-TS files (Transportstream format) to the folder /Qmultimedia/TV/Record.

Playback recordings using smartphones or tablets

iOS: "Ace Player" supports browsing the QNAP SMB filesystem and is able to playback the MPEG-TS files of previous recordings
iOS: A 3rd party app called "Qtv" (not created by QNAP) claims to be able to access live TV provided by "Digital TV station"
Android: "QVideo" app supports browsing and playback of the previously recorded files. Live TV channels can be watched as well. Necessary is a 3rd party app called "TVHGuide". It can access TV Channels, after choosing one of the channels there is an option to play it. The live TV stream can be accessed by QNAP app called "QVideo". (Configuration of TVHGuide: Hostname: your NAS IP address, Port: 9982, HTTP port: 9981, Media container: Pass-through, Prefer external player: mark this option to watch TV with QVideo app)

Being able to record weekly aired series with a single programming option. Currently it is limited to single programming using EPG.
VLC URL compatible streaming to VLC clients (e.g. iPad)
Apple Airplay streaming
UPNP/DLNA streaming

QNAP has an official page of supported TV Tuner hardware:

Furthermore the following DVB -T hardware has been found to work with the app "Digital TV station":

TV Tuner Hardware	Found to be working with QNAP Version
Freecom DVBT USB 2.0 Stick (Model 25452 from 2005-2007)	TS-119, Firmware V4.0.5, Digital TV Station V1.1.2