I've used Tomato Plus by Cooke, a p-chlorophenoxyacetic acid for heavier fruit set, with good results. Now my supply is gone, Cooke is no longer in business and the other calcium-based setting agents are ineffective. I haven't seen a product designed for tomato set in many years. The organic gardening mail-order firm Garden's Alive sells a blossom set product, but it does not say what chemical is used. Tomatoes set fruit from their own pollen.
Some gardeners use an electric toothbrush as a vibrator to disperse the pollen.
When used daily on flower clusters, this will help increase the pollination rate and enhance the crop. When temperatures drop below 55 degrees, pollen dies and no fruit will be produced. Even with the use of fruit set and shaking or vibrating, the crop is determined by the vagaries of weather. At the Cupertino Community Garden, some of our gardeners use diatomaceous earth to combat some pests. I have always used the pool-quality material, but some claim you should buy garden quality.