The app had fun matching and fill-in-the-blanks games, as well as a reward system of badges.

WSJ: Mobile Apps for Foreign Languages

It allowed the firm to fill in blanks to the third-party data it had licensed at a time when its own cartographers were focused on other territories.

BBC: Google Map Maker edit tools extended to cover the UK

By supplementing the GPS data with accelerometers and gyroscopes, researchers can use direction changes and speed to fill in the blanks, improving accuracy from a crude-at-best 49 feet to between 3 and 7 feet.

ENGADGET: New in-car GPS tech uses motion sensors for accurate, autonomous city driving

The options range from abstract, plot-free experiences to sparse narratives that invite the player to fill in the blanks.

WSJ: Gaming's Art-House Hits

Recently, companies such as Nolo Press and LegalZoom have advertised do-it-yourself wills and trusts, including instructions and forms to print out documents and fill in the blanks.

FORBES: Is Do-It-Yourself Estate Planning a Valid Option?