i would like to add now tv and Amazon prime apps to my app list on my TiVo box. Is this feasible and if so how do I do it
Short answer is no you can't.
Virgin owns the box, & the service that runs on it. The apps you have available are therefore the ones Virgin has signed agreements with the providers to use on its service.
Cable customer since 1993. Services: FH TV, Sky Sports & Movies (2xV+), Talk Unlim Telco, VIVID 100, Virgin PAYG Mobile