Police say the death toll in the Shoreham Air Show disaster is '"highly likely" to rise to 11.
Formal identification has yet to be given but the families of three of those killed have confirmed the deaths.
Mr Grimstone, who was a goalkeeper with the non-league club, was "the kindest person you could ever meet, with a great wit", his family said.
His parents Sue and Phil and brothers David and Paul said they were in "total shock" at his death, adding: "He was the kindest person you could ever meet with, a great wit.
"In his 23 years we can honestly say he never lost his temper."
The plane plummeted on to the A27 and burst into a huge fireball, ploughing across the busy road just yards from cars and a group of people.
The pilot, British Airways pilot Andy Hill, is fighting for his life in hospital in a critical condition.
Those caught up in the tragedy were remembered at church services this morning.
Prayers for the crash victims and their families were said at St Mary de Haura Church, where a minute's silence was held.
"It has really touched everyone and I really feel for the people who were at the airport yesterday and saw the event take place and of course the families of those affected.
"All these occasions like this show that the community is very robust and it brings everyone together. We are still in a state of shock about what's happened."
He added that he hopes the air show can continue, saying: "I would like to see it continue, it's been a part of Shoreham for a very long time. It's good for Shoreham and puts it on the map but unfortunately for something that's not good this year."
Several injured after a plane crashes at the Shoreham Airshow. Police declare major incident. pic.twitter.com/IeYgMYmfx1— Joshua Coupe (@JoshuaCoupeKM) August 22, 2015
The pilot survived but cyclists killed and people in cars injured... Horrific 😔 #Shoreham— Nicholas Hair (@NDH37087) August 22, 2015
Some 14 people were injured, four of whom were taken to hospital, after the jet crashed at around 1.20pm yesterday shortly after beginning its display in front of thousands of spectators.