It is the new Indivision scandoubler from Jens Schoenfeld of Individual Computers.
Yes it will work with A2500.
It works with A500, A500+, A2000, B2000, A3000, CDTV and A600 (in conjunction with A603 RAM card).
I have a feeling it might also work with A1000.
With the work that has already been done on the Indivision, Indivision AGA and Indivision 4000/CD32 Individual computers knows a lot about getting the best picture on a VGA CRT & LCD screen. No external generic scandoubler can come even close.
While it was announced in March, it is still not available to buy until later this year.