Transfer Files using Cloud.
You can transfer files using cloud services like Dropbox, Google Drive, Box, Skydrive or any other free cloud services. We recommend Dropbox or GoogleDrive while considering stability and platform support. You can create a shared folder in your Dropbox account for your friend and upload to the shared folder to access from both ends. Also read: How to Create File Shortcuts on Android Devices?
Transfer Files with Apps.
There are dedicated apps compatible with iOS and Android platform to transfer files between each other. Most of these apps are using either WiFi or Bluetooth. One of the free apps you can try is Send Anywhere (File Transfer) app. This app is available on iTunes and Google Play Store.
Transfer Files via Email
Email services are supporting the file size from 5MB to 25MB. If you have larger file than 25MB there are other workarounds to send a large attachment via email.
Please see this post to Send Large Attachments with Gmail and Yahoo Mail. Please see here to Send Email Attachments from Android.
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