Your phone goes everywhere, and so should your tools. Since you aren’t likely to be carrying a tool bag around with you, get this instead: IN1 Multi-Tool Case ($45). It’s a polycarbonate iPhone case (coming soon for Samsung!) that contains: two screwdrivers (one Phillips, one flathead), two ballpoint pens, a nail file, a pair of tweezers, a pair of scissors, and a kickstand. So no matter what, you’ll be all set.