Pokermind is a web application that it has been turned into a native Windows application thanks to Electron.js.
This framework is widely used and supposes no risk for your computer. For example, Skype and Discord are built with it.
Also, it's the only thing that's being installed in your computer because Pokermind runs on the cloud.
To avoid the block, click on "More info" and then "Run Anyway" on the Windows SmartScreen popup.