To install on Android or iOS: You should install this app for mobile devices directly from your app store. Click on the appropriate link on the main page or search for "Greek Study App" in your App Store and install the app as you would any other app on your device. You don't need to do anything else.
To sideload on Android: If you want to try loading the app on an android device without the Google Play Store, the "Android APK" icon on the main page will take you to a folder with all the APK versions of the app from the past year. They are numbered according to version number, except that there is no period between the major and minor number. So (as I write this) the most recent version is 2.14. That APK file will be labeled "214".
Sideloading on an Android device is not difficult, but it does require that you enable the installation of apps from outside your device's App Store. (Google for how to do this on your particular device.) Needless-to-say, there's a risk in doing this. If you turn this off to sideload this app, I suggest you turn it back on again afterwards. And be aware that you are trusting me (like with the desktop versions) when you load the app from an APK.
Once you've enabled app installation from outside sources, you can download an APK file directly to your android device and try to install it. Obviously I have no idea if any of these versions will install and/or run on your device, but at least you can try. Also remember that an app you sideload will NOT upgrade automatically like it will if it comes from an App Store. So if you want to keep the app up-to-date, you'll need to check the main page of this site periodically and then download and install new versions as they come out.
To install on Windows: The installer file which is downloaded is a zip file called either "GreekAppInstaller_Win32.zip" or "GreekAppInstaller_Win64.zip" depending on which icon you clicked on. Unzip that archive and the run the program "GreekAppInstaller.exe" which is inside the folder "Greek App Installer". Since you downloaded this program from the internet, Windows will warn you that it is unrecognized and could be harmful. Assuming you trust me, 😊 click the underlined line near the top which says, "More info" and then click the button "Run Anyway" which appears.
The "GreekAppInstaller.exe" program will find the latest version of the "Greek Study App" program, download it, and run the Windows installer. Follow the prompts of the Windows installer to install the "Greek Study App" program itself. After you have installed the program, you can delete the zip file and the "Greek App Installer" folder.
To install on Macintosh: The installer file which is downloaded is a zip file called "GreekAppInstaller_MacOS.zip" Unzip that archive (Some versions of MacOS will unzip it for you automatically) and run the program "GreekAppInstaller.app". Your Mac will ask you to confirm that you want to run the program since it comes from the internet. Assuming you trust me, 😊 go ahead and run the program.
The "GreekAppInstaller.app" will find the latest version of the program, download it, and run the MacOS package installer. Follow the prompts of the MacOS installer to install the "Greek Study App" program itself. The program is called "The Greek New Testament Study App" and will be installed in your "Applications" folder. After you have installed the program, you can delete the zip file and the "GreekAppInstaller.app".
To install on Linux: The installer file which is downloaded is a zip file called with "GreekAppInstaller_Linux32.tar.gz" or "GreekAppInstaller_Linux64.tar.gz" depending on which icon you clicked on. Extract the "Greek App Installer" folder from that archive and the run the program "GreekAppInstaller" which is inside that folder "Greek App Installer". Since the program is an executable, you may have to confirm that you want to run it as a program.
The "GreekAppInstaller" program will find the latest version of the "Greek Study App" program, download it, and install it for you. It will place ".desktop" entries on your desktop and under the "Education" tab of your Programs menu. After you have installed the program, you can delete the tar.gz file and the "Greek App Installer" folder. Please note that the program will be installed only for your user; there is no option at the moment to install the program globally.
Once installed on your device of choice, run the app and click the "About" icon in the navigation bar at the bottom of the app for usage instructions.
I hope the app is fairly intuitive so you can just start using it. But there are a lot of features that you'll never know about if you don't read the usage instruction, so take a few minutes when you have the time and look through the "About" screen.