Send Files is a simple simulation of copying contacts, messages, gallery etc. form Android to iPhone. It's a quick tool to transfer all your personal data between Android and iOS systems. You don't have to do it manually - this app contains useful step-by-step tutorial how to transfer every kind of data to Apple system.

For simplicity’s sake, we’ll assume you’re set up on Android Device with your data plugged into Google’s services (Gmail, Google Calendar and so on). If you’re using something else, like a Microsoft or Yahoo email address, the process will be similar, and often just involves installing the relevant Android-analogous app on your new iPhone.

If you have issues moving your content, there are a couple of things that you can check:
Make sure that you leave both devices alone until the transfer finishes. For example, on your Android device, the Move to iOS app should stay onscreen the whole time. If you use another app or get a phone call on your Android before the transfer finishes, your content won't moving.

On your Android device, turn off apps or settings that might affect your Wi-Fi connection, like the Sprint Connections Optimizer or the Smart Network Switch. Then find Wi-Fi in Settings, touch and hold each known network, and forget the network. Then try the transfer again.
Restart both of your devices and try again.
On your Android device, turn off your cellular data connection. Then try the transfer again.
Ensure both devices are connected to the same WiFi network and then run the app.