Johns, 35, died suddenly Friday from a blood clot in his ankle. Sources say a memorial will likely be held in the United States, though friend Kevin Haaland tells PEOPLE everything is "still up in the air," as the singer's family travels from his native Australia to be by the side of his wife, Stacey.
"I don't think anything has been concrete yet," Haaland says of funeral plans. "I'm sure something like that will go on. I can't imagine that it wouldn't. There were so many people who loved him."
Famous well-wishers include former Idol judges Simon Cowell, Randy Jackson and Paula Abdul, who all Tweeted their condolences.
Season 13 champ Caleb Johnson, who says he admired and "looked up" to Johns before he landed on the reality show himself, dedicated a tour stop to him over the weekend. The two met at a movie theater in Los Angeles a couple months ago, when Johns warmly complimented the newly minted winner, Johnson says.
"That was just a magical moment," he tells PEOPLE of honoring Johns at the Idol concert. "You got that feeling and that warmth, and the audience was great with it. It was just a really powerful moment. My thoughts and prayers go out to his friends and family, because I know this just has to be a shock, and it's a tragedy."
Haaland says Johns touched the hearts of everyone he met.
"He was a special guy for sure," Haaland says. "Outside of the crazy voice and musical talent that he had, he was also just genuinely one of the funniest people to ever walk [the Earth]. He loved to laugh and to make other people laugh, and people just wanted to be his friend."
Haaland also tells PEOPLE that the duo were in the midst of recording new songs together – unfinished tracks that he may never release.
"I really don't know at this point," he says. "I haven't been able to bring myself to listen to him sing yet."
I just heard the very sad news that Michael Johns has passed away. A truly great guy. Rest in peace Michael.— Simon Cowell (@SimonCowell) August 3, 2014
So Sad. Too soon. Thank you for sharing your talents with us. RIP Michael Johns— Randy Jackson (@YO_RANDYJACKSON) August 3, 2014
I'm heartbroken over the loss of @michael_johns.His enormous talent, gigantic heart & infectious personality will live in my heart forever.— The Real Paula Abdul (@PaulaAbdul) August 3, 2014