Mathias Foster, also 17, said: "We won't forget it, it motivates us right through our business careers."
"It sort of pulled us together tighter," he said.
Two other members of the team are Jamie's cousins Regan Wearmouth, 18, and Jed Wearmouth, 17.
The fifth shareholder, Stirling Smith, 17, has taken over Jamie's role of sales manager.
The company has sourced coffee and coffee-making machinery from a Melbourne company, Zest, and the students have developed a new app that helps cafes order their coffee and keep track of its delivery and invoicing.
"There's nothing like that in the coffee industry," Stirling said.
The six founders all put their own savings into the venture and have raised more than $10,000 from investors. They won a Northland "dragon's den" competition and hope to get to the national Young Enterprise Scheme final in Wellington in December.
Their first customer, Bianca Hartley of Cafe Bianca in Kaiwaka, said she sold only Apollo coffee and was already getting rave reviews.
"I was just reading one today. A tourist coming through said it was the best coffee they had in New Zealand, it's a 10 out of 10," she said.
Westmount School regional principal Phil Muir said the team showed "resilience" by carrying on after Jamie's death.
"Jamie was a wonderful, full-of-beans young man," he said. "These things do have an impact, but we have monitored the campus very closely."
The private decile 9 school has 1670 students at 11 campuses from Kerikeri to Invercargill and says on its website that it is "committed to a way of life that is governed at all times by the Holy Bible".
The Kaipara campus opened in 2006 and is now the school's biggest site with just over 200 students in years 3 to 13 drawn from as far afield as Warkworth and Dargaville.
The school is owned by the Plymouth Brethren Church which had 5388 followers in the 2013 Census.