"There’s an app for that,” so the old iPhone slogan goes.

But in a country like Japan that’s struggling to find enough engineers and programmers, locating someone who can create an app is easier said than done.

That glaring need has fueled investor expectations for local startup Yappli Inc., which designs off-the-shelf apps that clients can manage locally without needing to hire programmers. Its shares have almost doubled since its Tokyo listing at the end of December, giving it a market cap of about $700 million.