I want to commercialize my MKR1000 project. My question is how the consumer will connect to their WiFi? I will be having a mobile app to help the consumer with initial setup but since consumer's Wifi SSID and password are not saved on MKR1000, how will the initial contact made with MKR1000 to save SSID and Password?
I've never used the MKR1000, but I'm guessing it is similar to the ESP8266 WiFi module.
You can set up the board as a WiFi access point (please use encryption, otherwise you'll broadcast your unencrypted password to all WiFi sniffers in a 50m radius). Then the user can connect to the board directly (using his phone or laptop) and enter his WiFi credentials in a web form. Once they are received by the MKR1000, it will try to connect to the WiFi network the user entered.
Remember to keep this access point open, even if the user has already entered the information, otherwise your device will be useless if the user uses it outside of his own WiFi's range, or if he changes his WiFi password or SSID.
My experience is also limited to the ESP8266 but I would say it is the same as described by PieterP. I'm looking at a clock project I found Buxtronix: ESP8266 based NTP Clock which gets its time from an internet NTP server. Initially the clock is put in Access Point mode and the user feeds in, via a web browser on a smart phone, the main wireless lan credentials. After that, the clock switches to station (wireless client) mode, contacts the main wlan and fetches data from the internet.
You may need an exposed button on your product with which the user can force a reset to re-enter/change the main wlan credentials.
If the user is then going to contact your device through the local network, you'll have to think about how he knows with IP address it [the device] has obtained or been configured with.