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.
With every file type that is downloaded from Internet explorer (or your e-mail), there should be an application associated with the file type to open it. When the file is downloaded, the associated application will help read its contents. For eg: 1  PDF-Adobe Reader App.