Forums in the Mobile Apps Niche

1. GolfWRX
Forum has 174,079 members.
http://www.golfwrx.com/forums/  

2. PetGroomer.com GroomerTALK and
Pet grooming forum for dog and cat groomers and mobile.
http://www.petgroomerforums.com/chat/forum.php  

3. BattleOn Forums!
https://forums2.battleon.com/f/  

4. PPCGeeks
PPCGeeks is a site for PPC owners with discussion, reviews, news, links, downloads, and much much more. We cover Windows Mobile, Android, Windows Phone 7, Blackberry, iOS, and tablets.
http://forum.ppcgeeks.com/  

5. KVR: Forum Index
KVR Audio Forum - Forum - VST Plug-in, AU, AAX, Audio Software Discussion
https://www.kvraudio.com/forum/  

6. MacRumors Forums
Apple news and rumor discussion
http://forums.macrumors.com/  

7. Overclockers UK Forums
Just missed out on a spot in the top 25.
http://forums.overclockers.co.uk/  

8. forums.crackberry.com
The #1 Community Forum for BlackBerry Users & Abusers! BlackBerry Help, Discussion, Rumors and More...
https://forums.crackberry.com/  

9. Wacom
Forum has 6,592 posts.
http://forum.wacom.eu/  

10. Cell Phone Forums
Forum has 806,276 posts.
https://cellphoneforums.net/forum.php  

11. R2IClubForums
Return To India
https://www.r2iclubforums.com/forums/  

12. Fantasy Football - Footballguys Forums
Many people go football crazy over sports forums like this one.
https://forums.footballguys.com/forum/  

13. Wilders Security Forums
Community Based Discussions about Online Privacy, Security and Data Protection
http://www.wilderssecurity.com/  

14. iPhone, iPad, iPod Forums at i
Discuss and get help with iPhone, iPad, iPod touch, iOS, and iCloud
https://forums.imore.com/  

15. VideoHelp
This forum will help you with all your video and audio questions!
https://forum.videohelp.com/  

16. BleepingComputer.com
A free community and discussion forum for answering Computer Help, Security, and Technical Support questions.
http://www.bleepingcomputer.com/forums/  

17. Google Community
The #1 Unofficial Google Forum to discuss and chat on the use of Google products and services, such as Gmail, AdWords, AdSense, Analytics and YouTube.
http://www.gforums.net/  

18. Tech Support Guy
Just missed the top 10.
http://forums.techguy.org/  

19. VBForums
Visual Basic Discussions plus .NET, C#, game programming, and more (http://www.VBForums.com)
https://www.vbforums.com/forum.php  

20. Ubuntu Forums
A help and support forum for Ubuntu Linux.
https://ubuntuforums.org/  

21. CodeGuru Forums
Hard hitting articles, dicussions, resources, and more all focusing for real developers in the real world.
https://forums.codeguru.com/index.php  

22. DonationCoder.com
DonationCoder.com Forum - Index
https://www.donationcoder.com/forum/  

23. UAV Coach Community Forum
https://community.uavcoach.com/  

24. Zend Forums
This PHP blog includes articles from experts about PHP development, security, best practices — and more.
http://forums.zend.com/  

25. Java Forums at the Big Moose S
https://www.coderanch.com/forums/  

26. Apolyton Civilization Site
Forum Description
https://apolyton.net/forum.php  

27. Bitcoin Forum
Bitcoin Forum is a community of developers, academics, and entrepreneurs dedicated to promoting and improving Bitcoin.
https://bitco.in/forum/  

28. Long Distance Relationship Forum | Loving From A Distance
Forum has 340,524 posts.
https://members.lovingfromadistance.com/forum.php  

29. My Local Services
Welcome to our 100% free and friendly Small Business Forum. Gain advice, help and join in the business discussion and banter.
https://www.mylocalservices.co.uk/forum/  

30. Viewing list of forums
The SoundDomain forum is the place to go for all your car audio, stereo, installation, and mobile video questions.
http://forum.sounddomain.com/ubbthreads.php  

31. Geocaching Forums
https://forums.groundspeak.com/GC/  

32. Digital Spy
Digital Spy Forum and Community, a place to discuss the latest TV, Movie and entertainment news and trends.
http://forums.digitalspy.co.uk/  

33. GameSpot
Join the discussion around video game news, reviews, previews, and walkthroughs for the PS4, Xbox One, PS3, Xbox 360, Wii, PC, 3DS, and DS.
https://www.gamespot.com/forums/  

34. RESET Forums (homeservershow.com)
Forum has 78,275 posts.
https://homeservershow.com/forums/  

35. Webmasters, SEO, Internet Marketing & Digital Marketing Forum
The #1 internet marketing forum for marketers, SEO specialists, webmasters, web hosting, affiliates and a marketplace to buy and sell services.
http://www.webmastersun.com/  

36. 3D Robotics Drone Forum
3D Robotics Solo Drone Information, Forum, Help and Community
https://3drpilots.com/  

37. Beyond3D Forum
The world's best online 3D graphics discussion!
http://forum.beyond3d.com/  

38. Sports Card
Forum has 1,939,556 topics.
https://www.sportscardforum.com/forum.php  

39. Cathe Friedrich Fitness Forums
Cathe Friedrich forums about fitness, health, nutrition and workouts.
https://cathe.com/forum/  

40. Neowin
News, Reviews & Betas which includes large community peer support
https://www.neowin.net/forum/  

41. www.skimble.com
Skimble forums.
https://www.skimble.com/workout-trainer/forums/  

42. www.elitetrader.com
Elite Trader is the #1 site for traders of stocks, options, currencies, index futures, and cryptocurrencies.
https://www.elitetrader.com/et/  

43. SysOpt Forums
This is a discussion forum for all aspects of computer systems optimization and customization
https://www.sysopt.com/forum.php  

44. The Niche Laboratory Forum
A new forum for discussing niche sites and making money online.
https://www.nichelaboratory.com/Forum/  

45. Keeptouch Community Portal
Keeptouch Community Portal is an online community based in Singapore, offering a place for exchange of ideas and information in a wide range of topics in the form of forum discussions and Internet...
http://forums.keeptouch.net/  

46. [H]ard|Forum
HardOCP Community Forum for PC Hardware Enthusiasts
http://hardforum.com/  

47. Best Destination Wedding
The #1 Destination Wedding Planning resource. Get help from other brides, read photographer & resort reviews, DIY invitations, OOT bags & lots more!
http://www.bestdestinationwedding.com/f/  

48. Squeezebox : Community : Forums
Squeezebox Forums
https://forums.slimdevices.com/  

49. Affiliate Marketing Forum | AffiliateFix
Affiliate Marketing Forum | AffiliateFix. The number one Affiliate and CPA marketing forum online. Affiliate Networks and more.
https://www.affiliatefix.com/  

50. Supercell Community Forums
Supercell's official Community Forums for all fans of Clash of Clans and Hay Day! Join today!
http://forum.supercell.net/forum.php