On one recent occasion, Mr. Saleh asked Mr. Rametra to join him for a game of tennis, but Mr. Rametra said he didn’t have a racket, he recalled.
“He was like, ‘I already got you one, let’s go,’” Mr. Rametra said, crying. “I never got to play with him.”
Mr. Rametra, 31, also lauded Mr. Saleh’s business acumen, saying that his friend was a visionary who was always looking to his next idea.
“He was a machine, dude, he never stopped,” Mr. Rametra said. “He was always trying to make money.”
Mr. Saleh grew up near Poughkeepsie, N.Y., according to public records. As a teenager, he learned to code and began to develop websites, his friends said. He graduated from Bentley University, a small college in Waltham, Mass., in 2009 with a degree in computer information systems, according to his LinkedIn profile.
On social media, in interviews and blog posts, Mr. Saleh depicted himself as an entrepreneur driven by passion.
“Entrepreneurs are the ones that really change countries, that really change cities,” Mr. Saleh said in a YouTube video in February. “They’re the ones that bring the vision.”
After college, Mr. Saleh turned his love for practical jokes into a prank-calling app named PrankDial, which allowed users to buy prerecorded calls to send to friends.