An eGFR blood test is used whenever there is suspicion of a kidney disease. This is usually the case in patients who are suffering from diabetes or from hypertension for a prolonged period of time.
In the case that your APP file doesn't open, it is highly likely that you do not have the correct software application installed on your PC to view or edit APP file extensions. If your PC opens the APP file, but it's the wrong application, you'll need to change your Windows registry file association settings. In other words, Windows is associating APP file extensions with the wrong software program.
If none of your installed apps can open the file, search the Internet or Mac App Store for apps that can play or convert the file. Include these in your search: The name of the media format. If you don't know the format, select the file and press Command-I to open an Info window.