Run the AppImage once the download has completed. Select "Integrate and Run"
If you do not wish to use AppImageLauncher, you will have to manually allow executing the AppImage as a program, and you will have to manually install the App in your system.
To start SonarView, select it from your distro's application menu
Then the registration screen is presented to you.
Enter your email and hit return or press the Send button. A one-time registration code will be emailed to you and you can enter it on the next screen presented to you. Once registration is complete, the app will go into Device Discovery mode on the next page.