I counted 15 blossoms on the tomatoes - that's counting every one that I see even a hint of yellow. There are maybe twice as many where I see buds but not yellow yet. Here's another picture of the blossoms.
To ensure pollination I have been running the fan the last few days. But we've had so many issues already I didn't want to take and chances, so I used a technique I found online of touching the stems of the flowers with an electric toothbrush. I did see some little clouds of pollen, so I suspect it worked.