A multi-function and multi-task tool is best, especially when trying to keep weight down in your backpack.
TaskOne G3 from TaskLab fits that category. It is a protective case for a cell phone and built-in stainless steel tools to give the Swiss Army knife a run for its money. It's on sale at Sears for $59.95, while Amazon is selling it direct from TaskLab for $89.95.
It has a 2.5-inch knife with serrations, fixed blade. Other tools include a 1.8-inch saw blade, pliers with wire cutters, wire strippers, six Allen wrenches, flathead and Phillips screwdriver and a bottle opener. It is a great backpack item, in a pocket of a combat vest system, or kept in the glove box of your vehicle.
KRUDO Knives featured at the 2014 SHOT Show a cell phone that offers multi-tools that fits the iPhone and the Samsung Galaxy in competition with TaskLab.
Here is a video interview …
The only problem with the video is that the interviewer continually interrupted the guy demonstrating the product.
The TaskOne G3 offers more features (16 tools) and I suggest choosing over the KRUDO knife contraption. The KTC54 for iPhone comes with a 32GB Micro USB Thumb Drive and a weird shaped knife built in and Allen wrenches that are required to place cell phone into case. It lists for $267 and KTC54 for Samsung Galaxy S5 lists for $275.
Recommend the TaskOne G3 at $59.95 with more gadgets.