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.
Each window can display a different application, or it can display different files that have been opened or created with a single application (e.g., text, image or spreadsheet files). Moreover, there is a great deal of flexibility with regard to how multiple open windows can be arranged with respect to each other.