Google has a hidden iOS app that will assist you in making the conversion to Android.

According to 9to5Google, Google has secretly created free software for iOS that allows you to quickly transfer data out of an iPhone to an Android device. The Shift To Android app is wireless, so you didn’t have to think about using a cable to link the two phones.
According to the software’s description also on App Store, “the Switching to Android app by Google allows you swiftly and securely transport your most critical data kinds – images, movies, contacts, and google calendar — to a brand spanking new Android phone without finicky wires.” Messages aren’t included in that list, so the software won’t be able to transmit them. It will, however, take you into how to turn off iMessage so “you do not even miss emails and texts from friends and family.”
9to5google says It is an unlisted software, according to Google, and I didn’t locate it in the Application Store on my iPhone. You can, however, get it right now in this direct link. A request for information from Google regarding when the app could be formally listed just on App Store was not immediately returned.
Source: The verge