Applegate went on to write various hit songs for: Milli Vanilli ("Girl You Know It's True"), No Mercy ("Please Don't Go"),[19] La Bouche, Bad Boys Blue ("You're a Woman", Love Is No Crime album), Boney M. ("Young, Free and Single"), Banaroo, Bonnie Bianco, Jennifer Rush, Far Corporation, Aaron Carter („Crazy Little Party Girl“), Liberty ("Thinking It Over") and Le Click.
She worked with: Nena, Udo Lindenberg, Dieter Falk, Tic Tac Toe, Funky Diamonds, Culture Beat (Metamorphosis) Yoomiii, Jazzamor, Cascada, Pur, Erkan Aki,[20][21] Pete Seeger[22] and Gotthard (Lipservice album).
Applegate also left a footprint in the German Pop- and Schlager world, writing for acts like: Thomas Anders, Nino de Angelo, Matthias Reim[23] Michelle and Helene Fischer.
Her debut was on the Wolfgang Petry album "Auf das Leben", which was released in September 2021 and ranked at number 2 in the German music charts.
Applegate won 2nd place together with Victor Drobysh in the 2012 Eurovision Song Contest with the Russian entry "Party for Everybody" performed by Buranovskiye Babushki.
Applegate collaborated with Frank Farian and Michael Stark on the storyboard for the Daddy Cool musical which opened in London's West End at the Shaftesbury Theatre in 2006.