We have been seeing breakthrough flea problems with our clients who have been using frontline religiously on their pets. The vets feel the fleas are developing a resistance to the Frontline. I wouldn't recommend using it anymore, especially if you're seeing fleas while using the product. I have not heard of the spray you're talking about, but some products we use and recommend to our clients are Revolution, Comfortis, and Vectra 3D.

As far as I'm aware, though, the tick efficacy portion of Frontline is still working well, just not the flea preventative portion.