Cell Phone Bike Holder

I use an app on the phone as a bike computer, so this holds the phone firmly in place and allows me to see some info live. The lower section is for a battery pack, so that I can leave the screen on all the time.
You won't be able to use this as is... this is extremely specific for my bike and my phone (sony xperia z3 with cover on) and battery pack. However, I added a step file, so you could modify this to fit your bike and phone, or maybe, like me, just get an idea to make your own (see the remix section for where I got the idea from - thanks guys!).
I placed some padding inside to dampen vibrations to the phone, and the thing is held in place with tie-wraps, as you can see on the pictures.
I later printed a dummy battery pack, because I don't always need the real one, and when it is not there, the floor holding the phone gets a bit flimsy and flexy, so the dummy battery pack makes sure everything is tight.