Connor Tumbleson aka XDA Senior Member iBotPeaches has released an update to the ever popular Apktool, which now supports Android 6.0 Marshmallow API 23, and it also includes updated v2.0.8 of the smali/baksmali project.

You can find the official update blog post here along with a XDA post on the update. Download links for the latest version can be found there as well, including instructions for migration.