Also, how to I put both x86 version and ARM on google play?
The two APK files inside the ZIP are named as follows:
1. YourAppName.android.crosswalk.x86.timestamp.apk, e.g., CrosswalkExampleApp.android.crosswalk.x86.20140418132640.apk
2. YourAppName.android.crosswalk.arm.timestamp.apk , e.g., CrosswalkExampleApp.android.crosswalk.arm.20140418132745.apk
This Google Play Store* Submission Process document will walk you through the process of submitting multiple APKs to the Google Play Store for distribution under a single application listing. By following this procedure you insure that your Crosswalk application is available to the widest consumer audience. The store will automatically provide the appropriate architecture file with no special intervention on the part of your customer.
EDIT: Since I have no right to paste URL here to link a PDF documentation about how to submit multiple apks to Google play store. You can google it with keyword "intel multiple apk submission".