I installed NavFree on my android phone yesterday so I thought I would share my impressions since I couldn't find much Thailand specific info on this application.

Install was easy and quick and the Thailand map download took about 10 minutes via WiFi.

Simple and easy to use so far though I am just getting started with it.

Uses open source maps which are a bit hit and miss on coverage, some small roads are missing but generally not too bad.

I am not in Bangkok so I don't know how it handles the elevated flyovers and toll routes.

On a 5" phone screen the pop-up adds are annoying and consume to much of the available display.

Overall a pretty darn good app to have for free.

If I was using navigation regularly I would likely pay for Sygic but I rarely need a nav program so this free one is good enough for me.

I'll stick with Sygic as well. Tried the others, not impressed. Sygic will run forever in free trial mode if you need to.

Go for HERE maps by Nokia. It is free, the maps for over 70 countries are well maintained and updates are free. Visit the website at http://here.com for more information. I used the software for several longer trips already, generally it works very well. There is one error in routing from Surat Thani to Chumphon, but it does not require a navigation system to use the normal highway on that route. If you are online, it will update on traffic jams while on the go.

You can find the software in Play Store or download from the website.

Have a safe ride!

Sygic is also free now , if you dont need the premium features it will work well

Its a shame that Navifree street names are in Thai because that seems to be the best app found loads of POI's that the others couldnt, juts a shame cannot read the roads!!