Brewersfriend.com is optimized for mobile displays. No real need for an app, per se', although they do have one on Google Play. It's mostly just a collection of calculators etc. The website is the way to go.
Fermenting: #21 Bishop's Notty Smash IPA
Fermenting: #20 Ol' Bishop's Jolly Holiday Grog
Recently consumed: #16 Bishop's Tarbaby Coffee Porter, # 17 Bishop's Tall Two-Bit Blonde #18 Bishop Garity's Irish Red, #19 Bishop's Great Pumpkin
Planning to brew: Bishop's Great Pumpkin, Strong Scotch Ale