This Xposed module adds a Download option to Vine. Clicking that will download the video to a Vine/ directory under your usual downloads directory.
This requires the official Vine application, the Xposed framework only runs on ICS+ so this will only work on ICS or above.
The mod is open source, and licensed under GPLv3: https://github.com/MohammadAG/Xposed-VineDownloader
You may not distribute this on the Play Store.
If you found this mod useful, consider donating with PayPal.
@rovo89 for his awesome framework, and helping me out with an issue in this module.