Google Play Store is a place with thousands of apps for android phones and tablets. You can download the apps from Google Play on your phone but it just installs automatically, you can't locate the file where it is downloaded.
If you have a high-end phone with standard hardware, almost all of the apps on Google Play Store will be compatible with your phone. But if you have a phone with pretty low hardware, you may get errors like the app is not compatible with your phone.
What if you really want to download the app on your incompatible phone in such situation? The only option remains is to download the APK file of the app and install it manually or copying it to the /system/apps folder. But from where can you download the APK file of the app?
This site allows you to download the APK files directly from the Google Play Store. You just need to enter the package name in the box and hit the button to generate the app download link. The site is very simple to use and solves the purpose. You can save the app on your PC or Mac and then transfer it to your phone and install it.
You can also download it by scanning the QR code. It also displays the package name, file size, MD5 file hash and the time when it was last fetched. They also have a Chrome extension using which you can download the app while browsing through the play store.