The 27-year-old made just a single substitute appearance for the Clever Boys in the last campaign after signing from Livingston, and has now returned to Scotland after being released at the end of the 2015/16 season.
“I enjoyed it in South Africa, it was just unfortunate that it didn’t really work out, but I’m happy to be back at Livingston,” he told the Daily Record.
“It definitely feels like I’ve come home. I’m very excited to be here. Obviously I spent a good few years here before and coming back feels like I never left.
“My fitness is getting there, I’ve certainly improved since I’ve been in training and I’m feeling a lot sharper and a lot fitter so I feel I’m getting close.”
Livingston were relegated to the Scottish third tier in Jacobs’ absence last season, but are runaway leaders in the league this campaign and well on course for promotion.
Keaghan and his brothers Kyle, Devon and Sheldon all famously played for Livingston in one game in 2010.
It is thought to be the only time in the history of professional football that four brothers have played in a single match.