The big striker, 33, is the latest Iron capture as they prepare for their National League comeback.
The South play-off winners have had a busy summer with manager Angelo Harrop determined that the club attack the challenge head on.
He pulled off a massive coup by landing imposing forward Effiong, who joins Kyrrell Lisbie, George Langston and Marley Marshall-Miranda in signing in recent days.
They will be playing for a coach who doesn’t want to be battling down the bottom end.
Former AFC Sudbury boss Harrop has been in charge at Cressing Road since 2022 and has just signed a new contract.
“I’m just so delighted I can give these young players the opportunity to showcase themselves of the National League stage now, they deserve it,” he said after winning promotion last month.
“I’m realistic. We are going to need to evolve and we are going to need to evolve really really quickly.”