This object holds a phone on your forearm.  It is customizable to any arm size and phone size, but is sized for my arm and my phone (an iPhone 5s with rubberized case).  You will need to change the variables at the top of the file to fit your am and phone.  The phone mount is a friction fit to your phone, preferably one with a case on it made of rubbery material to help in the friction fitting.  You can also modify the hole size and number on both the phone mount and the arm band.  In practice, I used Slic3r's brim feature to make sure it would stick to the bed properly and the gauntlet in the photo is about a 75% complete run, stopped early by accident.  Also the print will need lots of sanding to smooth it out so it does not irritate your skin.  A Dremel tool or approximately 100 grit sandpaper is recommended for that.  I call it the Nerd Power Gauntlet because I plan to add holders for other things like wallet, keys, pen, and so on.  Use this idea and OpenSCAD file as a starting point and design your own Nerd Power Gauntlet!  Les