I have not seen many good free apps for brewing but this one is useful.
It's called Convert Units. Great for converting all of those weird measuring problems you think you would never ask, How many teaspoons Ina gallon. Pints In a liter and so forth.
Grinders Island Brewery - Pipeline
145 batches and counting
West Coast Blaster #4 almost go and on tap and a Dbl Chocolate Stout aging/carbing. Brewing East India Porter #4