I recommend in any case to set the instructions to take at hand (even if only by little things like the light signals of the device to be understood correctly). It's really not that hard! I could easily wemo, exclusively using my iPhone, set up.
One should definitely, directly after having the device connected to the Internet, perform all firmware updates! These take place step by step (ie not equal to the most recent, but version for version). In my case, 3 were required updates to the current version.
I recommend the iPhone to the latest firmware is installed in exactly the same WLAN (Sub -) - einzubuchen network. How it works most reliably. If the firmware up to date, you have to not be on the same wireless network. You can even control the wemo then via mobile network! The fastest the wemo reacts at least if the iPhone is logged in the same Wi-Fi!