You can send apps to friends as gift by going to iTunes. Launch iTunes on Mac/Windows > Go to App Store > Find and tap on the app that you would like to gift > Click on the arrow next to the “Buy” button. Then you will get a pop-up window with a “Gift This App” option > Click on Gift This App and fill out the information needed > Click on Next.
You can also send apps on iPhone/iPad. Open App Store on your iDevice > Find the app you wish to deliver as a gift using the browser or search function > On the app details screen, tap the share box in the upper right corner > Tap on Gift button when the menu pops up at the bottom of the screen.