This is what I use:
TopeakŪ Cycling Accessories ? Products - Wedge DryBag, black, medium (Strap Mount)
I'll save you the keystrokes and just admit that it is totally fugly.
However, I'm in Tampa with the rainy season beginning, so I'm not worried AT ALL about anything getting wet inside.
I have a tube, Pedro's tire levers, slim wallet, iphone 6, and my keys in there.
I, also, put my keys and phone in zip lock bags for total, over-the-top, OCD, Mr. Meticulous safeguard.
Glad to help!
S