What is this tree growing in my town?
It looks like a white crab apple or an obscure cultivar of apples, of which there are many. 

The best identifier will be the fruit. Because there are not millions of flowers, It looks like there may be less fruit and bigger than a crab apple, although it varies by year. 

The fruit of crab apples are small apples which can be used to make jelly. Crab apple trees can grow to 10m, a lot bigger than table apples. 

White flowering crab apple:


https://en.wikipedia.org/wiki/Malus

comparison images.