Lord Sugar rejected his pitch during the last series of The Apprentice as useless, asking: "Who could be bothered with it?"
The idea is Whisk, a service that creates online shopping lists based on recipes. The website will allow customers to convert recipes automatically into shopping lists within online supermarkets.
During the show Holzherr was beaten to Lord Sugar's investment by Ricky Martin, a recruitment team manager and wrestler from Portsmouth, who pitched a pharmaceutical recruitment company idea.
But Holzherr didn't give up on his idea. Speaking to the BBC, he said: "I was trying to stress to Lord Sugar and his advisors that you don't need a lot of money to build this.
"We're hoping we'll be able to generate revenue quite quickly."
Other Apprentice rejects who've gone on to secure investments include Suan Ma. Lord Sugar invested in Ma's skincare company Tropic, despite her originally failing to secure Sugar's £250,000 stake in 2011's Apprentice competition.
And Ruth Badger, who made it to the final in 2006 but was narrowly beaten by Michelle Dewbery, was hired by Lord Sugar for six months after the show.
Holzherr's story is just further confirmation that when it comes to The Apprentice, what counts is not necessarily the winning, but the taking part.