Mobolaji Akintunde, a Chicagoan who works in advertising and marketing, said he wanted a way to disguise his iPad when he was using it on the CTA. His fiance, physician Sofia Adawy, suggested hiding it in a book. They bought a cookbook at a Goodwill store, carved out an iPad-size hole with an X-Acto knife and covered the outside with fabric. “Over the next year or so, people would start looking at me,” Mr. Akintunde said. “They'd say, 'Did you make that? Man that's so cool. I wish I had one for my iPad.'” And so Mr. Akintunde and Ms. Adawy decided to go into business. Working with a local bookbinder, they've started taking preorders for the StacheBook — in four styles ranging in price from $79.99 to $99.99. Ms. Adawy says the first StacheBooks will ship to customers this month.