How cool would it be to have a Wifi Manager widget you could place in your project and forget all the programming and testing required to make such a function work?
Very cool I think. 
Or maybe… even better. A function in ‘My Devices’ where you could assign your hardware to a specific wifi connection?
I think that is called a “Commercial account product” 
https://www.blynk.io/
Besides… as for development level…how would the hardware know how to connect to the Server to get the needed connection info supplied by the App 
You mean to change the connection type of your hardware?
Blynk only works with a valid connection…
To change the wifi credentials there are better solutions that use a widget…
There is a library that lets you know if a double reset was performed (one reset after another in a short period of time) and, together with this, you can use another one to configure a wifi manager to modify the Wi-Fi connection data. With this you’ll make a special programming mode without waste any phisical pin. I use this on all my projects.
Are you sure you want to remotely change how a device connects? If something goes wrong … how do you fix it if it’s out of line?
Well, I’m not a tech guru obviously, so I’m just throwing ideas in the air and hope someone brings it down to earth. 
I see the problem with how to get the wifi credentials to hardware not connected to the internet, but Isn’t Wifi Manager doing this?
Nice trick… I think that would make a good Projects Made With Blynk topic.
the libraries i use are:
#include <WiFiManager.h> //https://github.com/tzapu/WiFiManager
#include <DoubleResetDetect.h> //https://github.com/jenscski/DoubleResetDetect
#define DRD_TIMEOUT 2.0 //seconds
#define DRD_ADDRESS 0x00
DoubleResetDetect drd(DRD_TIMEOUT, DRD_ADDRESS);
void setup()
{
if (drd.detect())
{
WiFiManager wifiManager;
wifiManager.setDebugOutput(false); //the librarie uses serial 4 debug info
wifiManager.startConfigPortal("SSID2CREATE","PASS4ENTER"); //a blocking line...
}
.....
}
This will create an AP called SSID2CREATE with authpass PASS4ENTER and the default ip to make changes in WiFi configuration is 192.168.4.1
The web displayed at this ip show you the near wifis and you can select one of them, write the connection password and after save it, the hardware will connect to the new wifi…
This is already done for business clients under the subscription. We call it provisioning process. http://help.blynk.cc/publishing-apps-made-with-blynk/1240196-provisioning-products-with-auth-tokens/dynamic-auth-token-provisioning
Ok, I see.
No chance for implementing this in the free version?
At the moment we do not consider this.
Does this prompt you to select a WiFi network while using the Blynk app?!
No, this let you to make a double-reset and when the program detects it… starts the wifimanager where you can select a wifi to connect, but you must be near the hardware to connecto to the AP wifi generated. This means you can change wifi configuration only locally.
The only way to select a wifi through blynk is be already connected to internet (WiFi,3G…) and sending new wifi auth and then making a remote-reset after that, the hardware will be connected to the new wifi.
What you need to do?
Well, you could consider to implement it in the free version, and make the widget expensive, say 1000 energy?? 
I think it would be a popular widget and generate some income for you as well. Win-win.