The audience for digital streaming audio – whether the content is from a local broadcaster or national outlet – is growing. Interestingly, the growth hasn’t come at the detriment of local radio outlets.

"What we’ve found is that 90 percent of people listen to the radio, and 80 percent of those listeners also listen to digital streaming," said J. Pat Miller, the director of marketing and innovation for WTMJ-AM 620 and WLWK-FM 94.5 in Milwaukee.

"And those numbers are from Nielsen. We knew we needed to have something more out there."

That something is what the Journal Broadcast Group called the "Radio League." I was part of the Beta test group when the streaming service started last year. The digital team has been working on making the streaming experience more robust. The group of radio broadcast stations started promoting the improved digital streams earlier this week.

"Journal Broadcast Group’s stations have joined the ‘Radio League,’ super-charging our existing smartphone app with the strength of local radio. Together their forces unite for a more powerful mobile music experience. The app is available as a free download through both the Apple App Store and Google Play Store," the official release stated.

Earlier today, I talked with Miller about some of the improvements.

"Artist and song title were the most requested feedback we received," Miller said. "So we knew we needed to have that."

Other innovations included refining some of the pure music genre-driven streams. Miller said that an example would be the classic alternative songs I hear in the '80s stream have been added to the adult alternative stream. And, depending on which market the listeners identify with, that the local streams can stay with them using a customized part of the app with a "favorites" button.

"Mobile is the fastest-growing way to enjoy our local stations, and the new Radio League app makes them all easily accessible while you’re in our local communities thanks to our innovative use of GPS," said Michael Gay, vice president of interactive media for Journal Broadcast Group. "A rock listener in Omaha doesn’t want a station from across the country, they want their local station front and center."

I asked about that too. The way I see it, if you listen to Spotify, Pandora or any other stream, if you like the music, you will continue to listen. Now, every broadcast stream from each of the stations in the group is available in the app. Localization that this app allows is a good idea for specialized broadcast events.

"We already have local high school football and basketball games in the stream under the WTMJ flag," Miller said. "We are in basketball season right now. We will have four live games on this week."

Summerfest is another good example of a custom station built around an event. Last summer, the Radio League featured music from the bands performing on many of the various stages on the grounds.

The Radio League app detects the user’s location and serves their local station first. Once the user picks a top station stream, the app offers the specific playlist, promotional messaging, social media and contesting.

"We work hard to build local brands that go beyond a collection of songs, and I’m proud our team has developed another way to deliver those products to the audience wherever they are," said Steve Wexler, executive vice president – radio for Journal Broadcast Group.  

In addition to the local stations, the Radio League app is paired with 14 pure-play digital music streams. The stations include "Now Trending Hits," "Nashville Edge Country" and "Solid Gold Oldies." Since the launch a year ago, the Radio League digital stations have continued to grow to a record audience of more than 55 million minutes streamed in the last month. 

"The digital stations offer additional choice beyond our broadcast stations.  The combination of on-air and online streams offers the best of both worlds for our audiences," Miller said.

Miller said he has been having a lot of fun with the new app, mostly because of the endless possibilities. "We can have as many different stations as we can find an audience to listen it. It’s been a great time playing around with it."

The digital world allows for tightening the scope on the listenership, where broadcast has to take more of a shotgun approach to reach more people as having a little something for everyone.

"Development of the Radio League app with the team at Journal was a great experience, and the result is a breakthrough mobile app," said Paul Jacobs, president of jacapps, the company that developed the Radio League app. "We achieved our initial goal of combining multiple stations across many markets in one app to create an outstanding local experience that is unlike other aggregated mobile applications." 

TUNE IN: Fox Business Network will air two new episodes of "Strange Inheritance," hosted by Jamie Colby on Monday. Starting at 8 p.m., a family inherits a museum of the largest private bug collection in the world. They learn it’s worth millions. The question will be if they keep the Colorado museum open or just sell the contents.

Then at 8:30 p.m., Colby meets with grandchildren that inherit a salvage yard. The episode, "Junk Yard Gems," was produced in Enid, Oklahoma. Turns out, the junk yard is filled with hundreds of pre-1940 cars. Colby takes viewers inside the business that houses the gems and tells the family’s story.