I would venture that the vast majority of horses get fed twice a day. Multiple feedings are great, but for anyone working away from home it's just not realistic.
As Chanda mentioned, hay nets keep hay in front of your horses at all times. Be careful to get one with openings small enough that they can't get a hoof caught, especially if you have one that paws. There are numerous types of slow feeders out there, from nets to pillows to grids that fit in tubs. I admit to being paranoid with my kids, so I'm still looking for the perfect, yet affordable, slow feeder.