They can't all be gems.

An iPhone application launched earlier this year by Kuawa Road Productions, the father-son team behind the $1.99 “;Ukulele Chord Kumu”; app last year, might chalk up the latest one to a learning experience.

“;We're only selling just a few,”; said Joe Uno, the dad half of the team.

Kuawa Road's “;RealityCheck”; app, for $1.99, follows the most popular reality TV shows, including “;American Idol,”; “;Project Runway,”; “;The Bachelor”; and many others. Each episode is covered with a write-up and tracks contestants week to week.

Purchaser goldeneye006 gave it five stars, saying, “;A good app but it would be nice if more shows were covered (besides the major ones),”; while LuckyLi26 gave it four stars and called it “;pretty good. I would give it five stars if they added pictures of the cast.”;

It is laborious to update. “;What we do is watch the show and basically put almost like a blog thing up,”; Joe said.

To add to their woes, detract from their potential audience or both, an established entertainment Web site launched a similar app it can populate via its considerable Web site.

Kuawa Road is competing against “;a 500-pound gorilla,”; he said.

Unlike the self-contained “;Ukulele Chord Kumu,”; Kuawa Road's “;RealityCheck”; is intensely high-maintenance, as is the duo's 99-cent NHLive app, which tracks and reports on “;who's playing tonight, today's games, games in progress, team rankings”; and player rankings, Uno said.

Some of the updating occurs automatically, as it is tied into a source for live scores, but “;my son does a lot of work on it every day.”;

Conversely, the low-maintenance “;Ukulele Chord Kumu”; “;is doing really well, selling like 100 a week all over the world,”; and has sold about 5,000.

The Unos are considering changing the business model for “;RealityCheck”; and “;NHLive”; apps to make them free but advertising-supported.

“;So you go with a free app and tie in these advertisers at maybe 5 cents a click. A million times 5 cents ...”; he mused.

Not yet raking in such click-through revenue, the pair is not yet ready to retire, Uno chuckled.

Separate from Kuawa Productions, his son George is getting mostly raves and five-star ratings for his 99-cent iPhone app called “;MW2 MAPS”; that contains all 16 multiplayer maps for the globally uber-popular video game “;Call of Duty: Modern Warfare 2.”;

Anybody with MW2 gamers in the household knows when a “;UAV recon is online”; or that somebody is “;Oscar Mike to the Whiskey Hotel,”; meaning “;on the move to the White House.”;

The game had racked up some $1 billion in sales as of January. Popular? Yeah, a bit. That's a lot of translucent blood spatter on TV screens and a lot of potential buyers wanting maps to “;pwn”; (gamer-speak for “;beat”;) online or real-life competitors.

This column has now reported on seven locally created iPhone apps, starting last August with the one that allows users to listen to KWXX-FM 94.7 in Hilo/101.5 in Kona; the aforementioned ukulele chord app; the Love Taps app, which helps users not become “;Opihi Man”; or “;Opihi Woman”; when in a new relationship; and most recently “;What Chefs Eat,”; to get honest-to-goodness chef recommendations on their favorite local places to eat.

Watch this space for news on a retail and shopping-focused app that will save users money.