I believe FFG built TOME in-house, so it’s pretty likely that they already have some developers. They’ve also built mobile apps to compliment their games (i.e. XCOM), which I think was done in-house, but I haven’t looked it up.
The glimpses I’ve gotten of TOME is that it’s a web app, so they likely have some kind of hardware infrastructure to be able to host it and allow all the stores that uses for all their games. They could possibly go in the direction of adding some kind of record keeping in their TOME infrastructure and it might not be a huge effort.
But, given how long it took to roll-out TOME, a year is definitely not too long.