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
138 batches and counting
European IPA bottled, One Putt 12 IPA carbing. East Indian Porter on tap. Looking into a Saffon Beer