(OTG Founder and , "We're seeing 15-20 percent revenue boost.")

Based on this success, OTG rolled out iPads inside restaurants.

One of the lessons learned was that industrial design matters. At first, OTG enclosed iPads in large metal boxes that were attached to fixed stands. People sitting at a table were supposed to share a single iPad. OTG began to think about adding split-check functionality to its custom restaurant menu app.

"It diminished the magic," Lee says.

OTG quickly made adjustments and now there's an iPad for every person, thus no need for split checks. The iPad can be held freely and used in either landscape or portrait orientation (although iPads have a leash to prevent theft). Meanwhile, waiters and waitresses wipe down iPad screens after every use.