Once you have downloaded and installed it on your smartphone or tablet make a search for 'huahin', HHF should be the only result. Click on the forum and login as you would normally, it will then be saved to your device (you can use the software to browse other forums also).
This video will help you familiarise yourself with it, you can browse and post by forum or by latest 'unread posts'.
If accessing the forum from a mobile device you should get an alert prompting you to download the app. You can adjust the settings, signature and alerts in the app also. There maybe some advertising displayed by the developers of the app of which HHF gets a share.
We have only installed this yesterday so it is all experimental, please post here if you have any questions and we'll do our best to assist.