|Platform(s)||iOS, Android, Apple TV|
2015 (Apple TV)
Smule is a music app initially released under the name Sing! Karaoke on iOS platforms in 2012 and subsequently on Android in 2013. In October 2015, Smule announced the release of an Apple TV edition of Sing!. Smule expanded its music experience to include the web in 2016, albeit in a consultative format for now. Smule has been described as "the biggest music app you haven't heard of" by CNET in 2018.
 In October 2017, Smule started offering official Disney duets starting with the song 'You're Welcome' with Dwayne "The Rock" Johnson's Moana character, Maui. It was the first of several animated duets that are available on the app. The Smule app also allows users to perform duets alongside top international artists such as Jason Derulo, Luis Fonsi, J Balvin, Charlie Puth, Polina Gagarina, Siti Badriah, etc.
Smule co-founder and CTO Ge Wang says the collaborative features should help with Smule’s broader goal of making music performance more fun and accessible. When someone opens a Smule app, he says they shouldn’t ask themselves, “Am I a musician?” because the answer is usually no. Instead, the goal is to draw people in, then by the time they realize they’re making music, “it’s too late — they’re already having fun.” With Sing, it’s it should be less intimidating to join in an already-created song than it would be to start singing on your own.
An update of the app added new filters such as one that made the user sound like they were singing in the shower.
Users choose a song and either sing along to it as a solo, duet, or group performance. Performances are uploaded to Smule's database, at which point, anyone can listen to them. Users can enable video recording mode if they want to record both video and audio. A private flag may also be enabled, if users don't want to allow others to listen to their recording.
148Apps said "Sing! Join the global karaoke party! is either going to horrify or delight people, depending on their point of view on karaoke, in general. Yes, there are a lot of bad singers out there, but the name of the game is to have fun, and with the whole world as a stage, Sing! can be an awful lot of fun." AppAdvice said "As far as music selection, the free app is a mixed bag." Appolicious concluded "That’s the beauty of Sing! It may or may not yield a Beyoncé, Snoop Dogg, Idina Menzel, John Mayer or even a Rebecca Black, but it is a wonderful way for singers the world over to unite and make a joyful communal sound."
- Dredge, Stuart (August 8, 2015). "Smule's new iPhone app would like to teach the world to Sing". The Guardian. Retrieved December 16, 2015.
- Maxham, Alexander (July 1, 2013). "App of the Day: Sing! Karaoke". AndroidHeadlines. Retrieved December 16, 2015.
- "Sing! by Smule for Apple TV Brings Home a Whole New Social Singing Experience". BusinessWire. October 29, 2015. Retrieved December 16, 2015.
- "Smule may be the biggest music app you haven't heard of". CNET. 2018-07-14. Retrieved 2018-07-18.
- "Disney's Moana fans can duet with The Rock on Smule's Sing! app". USA TODAY. October 4, 2017. Retrieved October 4, 2017.
- Ha, Anthony (August 8, 2012). "Music Startup Smule Promises To Get More Social, Starting With its New Karaoke App Sing". TechCrunch. Retrieved December 16, 2015.
- Takahashi, Dean (September 20, 2013). "With Smule's Sing! Karaoke app for the iPhone 5S, you can record songs in a shower". VentureBeat. Retrieved December 16, 2015.
- Culp, Dale (August 24, 2012). "Sing! Join the global karaoke party! Review". 148Apps.com. Retrieved December 16, 2015.
- Dirks, Brent (August 8, 2012). "Sing! Is A Fun Way To Do Karaoke, If You're Willing To Pay For It". AppAdvice. Retrieved December 16, 2015.
- Caplan, Lisa (January 12, 2013). "Smule turns the world into an iPhone karaoke party with Sing!". appolicious.com. Retrieved December 16, 2015.