If you’re the type of person who purchased a lot of apps on the App Store, you’re out of luck when it comes to transferring those to your new Android device. You’ll have to repurchase those. The good news, however, is that virtually every free app on the iOS App Store is also available on the Google Play Store. Whether or not all your data you’ve accrued on those apps will transfer depends on the app. If you’re unsure, get in touch with the developer directly.
On the music front, now that there’s an Android app for Apple Music, transferring your iTunes music to your Android device isn’t as frustrating as it once was. Apple Music is your best bet if you’ve actually purchased your music through iTunes as long as you have an Apple Music subscription to get your purchases.
Otherwise, it depends on where you get your music and how it’s stored. Any random MP3s you might have had would be transferred to Google Play Music instead. You can store up to 50,000 songs on Google Play Music for free. If you use Spotify or Pandora for your music, you can just download the Android apps for those services.
The biggest downside is any videos you may have purchased through iTunes won’t be transferred to your Android device, and won’t be available unless Apple gets around to developing an Android app to play them.