What App Works for AC1900 extender

[Scrimmer01]

I have a Nighthawk AC1900 Extender that needs to be set up again. The Genie app is no longer available and the Nighthawk App shows a message that this extender is not covered by it. Is there another app or means to set up this extender?

[plemans]

Just use the installation assistant. 

Did you set it up using the push button WPS option? 

If so, factory reset the extender and set it up using the installation assistant.

To factory reset, push and hold the reset button for 7-15 seconds while powered on. 

Here's a video of how to use the assistant. 

https://www.youtube.com/watch?v=yJVklshxBMk