Question: Who is known for his recurring role as Diggie on the Disney Channel sitcom, and is the co-star in an American pop duo from Los Angeles, California which consisted of "Liv and Maddie" ?

Context paragraphs:
Liv and Maddie: Liv and Maddie, titled Liv and Maddie: Cali Style for the fourth season, is an American sitcom created by John D. Beck and Ron Hart that premiered on Disney Channel on July 19, 2013, and ended on Disney Channel on March 24, 2017.  The series stars Dove Cameron, Joey Bragg, Tenzing Norgay Trainor, Kali Rocha, Benjamin King, and Lauren Lindsey Donzis.

List of Liv and Maddie episodes: "Liv and Maddie", titled "Liv and Maddie: Cali Style" for the fourth season, for the fourth season, is an American sitcom created by John D. Beck and Ron Hart that premiered on Disney Channel on July 19, 2013, and ended on Disney Channel on March 24, 2017.  The series stars Dove Cameron, Joey Bragg, Tenzing Norgay Trainor, Kali Rocha, Benjamin King, and Lauren Lindsey Donzis.

Joey Bragg: Joey Bragg (born July 20, 1996) is an American actor and comedian.  He is known for his role as Joey Rooney in the Disney Channel sitcom "Liv and Maddie", which aired from 2013 to 2017.  He also played Peter Magoo in the 2012 television film "", and co-headlined the 2015 Disney XD television film "Mark & Russell's Wild Ride".  Bragg has a successful stand-up comedy career.

List of Liv and Maddie characters: "Liv and Maddie", titled "Liv and Maddie: Cali Style" for the fourth season, for the fourth season, is an American sitcom created by John D. Beck and Ron Hart that premiered on Disney Channel on July 19, 2013, and ended on Disney Channel on March 24, 2017.  The series stars Dove Cameron, Joey Bragg, Tenzing Norgay Trainor, Kali Rocha, Benjamin King, and Lauren Lindsey Donzis.

Where Are You Now (Jimmy Harnen song): "Where Are You Now" is a power ballad by the Pennsylvania-based 1980s band Synch.  Co-written and sung by Synch band member Jimmy Harnen, the song was initially credited solely to 'Synch' when it was first released in 1986.  In 1989, the song was re-released under the name 'Jimmy Harnen with Synch'.  The song was featured on the Disney Channel sitcom, "Liv and Maddie".

Kali Rocha: Kali Michele Rocha (born December 5, 1971) is an American actress.  She is known for portraying Karen Rooney, the mother of four Rooney children and school's vice principal, in the Disney Channel sitcom, "Liv and Maddie".  She has also co-written four episodes of the show.

Dove Cameron: Dove Cameron (born Chloe Celeste Hosterman; January 15, 1996) is an American actress and singer, best known for playing a dual role as both title characters in the Disney Channel teen sitcom "Liv and Maddie" and starring in "Descendants" as Mal, daughter of Maleficent.  She reprised her role as Mal in "Descendants 2", which premiered on July 21, 2017, on Disney Channel.

The Girl and the Dreamcatcher: The Girl and the Dreamcatcher was an American pop duo from Los Angeles, California consisted of "Liv and Maddie" co-stars Dove Cameron ("the Girl") and Ryan McCartan ("the Dreamcatcher").  Their debut EP, "Negatives", was released on GDC Records on July 29, 2016.

Emily Osment: Emily Jordan Osment (born March 10, 1992) is an American actress, singer, and songwriter born in Los Angeles, California.  After working in several television films in her childhood, she gained fame for co-starring as the character Gerti Giggles in "" and "".  She went on to co-star in the Emmy-nominated Disney Channel sitcom "Hannah Montana" as Lilly Truscott as well as the series movie, "".  She also starred as Cassie in R. L. Stine's "" and the Disney Channel original movie, "Dadnapped" as Melissa Morris.  Osment expanded her repertoire into pop music and alternative/indie rock, where she has recorded teen pop hits like "I Don't Think About It", "If I Didn't Have You" alongside her "Hannah Montana" co-star Mitchel Musso, and "Once Upon a Dream".

Ryan McCartan: Ryan McCartan (born June 14, 1993) is an American actor and singer.  As an actor, he is known for his recurring role as Diggie on the Disney Channel sitcom. " Liv and Maddie", and for his role as Brad Majors in the 2016 Fox musical television film "".  McCartan is also known as one half of the pop duo The Girl and the Dreamcatcher.  McCartan also played Jason Dean, "JD" in the Los Angeles (2013) and the original off-Broadway (2014) versions of "Heathers: The Musical".

Supporting paragraphs: The Girl and the Dreamcatcher Ryan McCartan
Answer: Ryan McCartan