To be honest, I'm not really a web dev. I managed to install phpbb and modify it with some spam protection and customization tweaks, but full mobile support is a bit out of my reach right now. I'll need to invest more time to look into this and probably won't get around to this anytime soon.
The forum already has an integrated feed
for new postings though. So maybe you can plug that into some mobile app to notify you?
I used it in my emulator forum, it looked like pretty simple. All you need to do is spend some time to configure the forum name and category on their website. At least it was like that when I used it.