The company had 28 people when it was bought by the outsourcing giant in April last year.
Now it has 83 people and expects employee numbers to be close to 100 by the end of this year as it continues to develop its unique digital games and virtual environments which blue chip and public sector clients are using in training and recruitment.
As a result of the growth it has had to extend its headquarters in Lasswade, Midlothian,
Chief executive Mark Sutherland said: "By the end of the year we will hopefully be up over 100 [people]. Often as a small SME it is not quite hand to mouth but you are always working on the next project and you don't necessarily get the time or have the resource to take time out and innovate.
"With Capita we have had the luxury of being able to devote time and resource to innovate in new areas.
"It has allowed us to realise some new technologies."
Included in that is working in 3D with technology provided by virtual reality head set maker Oculus, which was bought by Facebook for $2 billion earlier this year.
There has also been adaptation of existing technology with some of G2G3's simulations now being used to recruit and assess graduates at Capita.
Mr Sutherland said: "Even though it was an old technology by our standards it was innovative in a completely different market sector."
G2G3 is also widening its research and development activities to look at applications in the wearable technology arena.
It is experimenting with cutting edge devices such as Google Glass as well as fitness related products such as the Jawbone Up and Fitbit.
Mr Sutherland said: "We constantly need to be innovating and look where the market is going.
"A firefighter in the [United] States had been working with [Google] Glass on how to cut cars. You integrate into a database for example to show you at a road traffic accident where you would cut cars safely to get the roof out to extract casualties.
"We are looking to that at how we can use Glass and augmented reality approaches as to how we can improve the experience of emergency services personnel."
On the fitness devices Mr Sutherland believes they could be used by local authorities to gather data on areas including CO2 levels in the air as well as monitoring the health of citizens.
Mr Sutherland said: "We are huge advocates of it ourselves as I wear my Up and it drives my behaviour.
"We have done some fledgling integration with Up and FitBit to look at how you could drive employee behaviour.
"I believe you could improve health. I've seen it with myself. I am much more conscious of what I eat and how I move.
"We think the wearable market is going to grow and grow so that it become pervasive."
G2G3 has also established a physical presence in North America through a takeover of Dallas, Texas, based company Plexent, through a deal which concluded earlier this summer.
Mr Sutherland said: "As our market continues to grow, particularly in North America, that will provide us with a good footprint on which to build."
G2G3 has continued to work with clients such as Ford, Microsoft and Bank of America since it was bought while Mr Sutherland admitted the deal has also opened a number of doors, particularly in the public sector with contracts with the likes of the Ministry of Defence.