This app is not downloadable but there is a way to replicate it and modify it to your needs.
The app is based on the US Geocoder tool in the Address toolset in Alteryx.
The US Geocoder is a macro so you can right click on it and chose "Open Macro: Portfolio Explorer.yxmc"
This was written in an older version of Alteryx so you will receive a message that Alteryx is automatically updating it to the current version.
You can covert this from a macro to an analytic app by looking at the one Macro Input to understand how the data comes in and replacing it with a Text Input tool (this would allow the user to enter the address.) You will also want to change the Macro Outputs to other types of Outputs.
The macro already has the Interface tools to modify all the common values (dataset for example)
One of the Interface tools triggers how the Geocoder deals with multiple matches (allowing the user to choose)
Thankfully the Geocoder macro is well documented with comment boxes.
Hope that points you in the right direction.