We use Antenna Mate on the iPad

Yep .. 

I'm a bit like Knightrider except that I observe all of the FIXED antennas on the CP roofs or local houses when I come into town and use them as a guide to direction and orientation.  I never rely on other campers.

I might just down load the apps in the previous posts, to join the current technology generation.

ps. For a long time I used a partial download from the DOC that listed all Au transmitters by location and direction with data on frequency, ID and orientation.  I've still got it somewhere but am too lazy to use it & I look a bit of a goose out there with my prismatic compass checking the direction of the local t'mitters  (perhaps I could use one on the smart phone - everyone stands there staring at their phones don't they).

I have 2 apps on my phone - DVB-T Australia and DTV Antenna. Both have their plusses and minuses. I look at other aerials around me in a caravan park, but the most reliable ones are those fitted to the on-site cabins. There are times when you are parked next to a cabin and your signal is blocked a bit. With Digital TV, it is either 'Yes I have a picture', or nothing, depending on how string the signal is at the time. Both of the above apps list the stations available and how far they are away from you. Also direction.

What is important is the power of the transmitters. We were recently parked at Mooree and where the van was there was no signal at all from the local transmitter. Obviously the sheds covering the thermal pools were blocking the signal. I checked the power, and it was something like 20 watts. I swung the aerial around to point somewhere else (I don't know where) and I got full strength signals. I checked the power of those transmitters and they were 75 kW - 75000 watts. Although they came from more than 90 km away, the net signal for me was much stronger. These phone apps give you these details as well as the direction.

We were then parked in Aspley Caravan Park in Brisbane. Yes - we know of its reputation, but we had absolutely no problems each time we have stayed there. The TV signals there came from funny directions as well - again probably because of interference with the par's on-site cabins. The phone apps soon sorted things out for me.