I have the rally armor mudflaps. Here's a picture of my car on the road leading to my house. I think it's obvious from the picture why I wanted bigger mudflaps
They do a good job of protecting against rocks and dirt getting on the side of your car, they will also help prevent rust in the future as you won't have rocks constantly chipping the paint off.
I think the biggest thing they do for the car is aesthetics though. Obviously, they're very noticable. I've always loved rally racing as a kid so I think it looks cool, but I know it's not everyone's cup of tea.
And to answer your other question, there is the Tapatalk app for reading forums which I know many people on here use.