Android: If you like the look of Ubuntu Touch, or just enjoy Ubuntu's overall colour scheme, Ubuntu Lockscreen can turn your boring old slide-to-unlock into something a bit more fun to use. The app supports app notifications, SMS alerts, password unlock and live animations, so it's functional and enjoyable.
Ubuntu Lockscreen is the work of XDA developer Rotary Heart, who has been working pretty tirelessly on the project for a while now. The lockscreen is designed to emulate the look of Ubuntu Touch, and notifications appear in the centre of the animated circle just under the clock on screen. Right now the app supports notifications for SMS and missed calls, but the developer is adding Facebook, WhatsApp, email and system notifications in the next update. It also supports music playback controls, so you can pause and skip songs without unlocking your device.
It's definitely in beta, so you may run into some bugs, but overall it works like a charm. Make sure to disable your stock or current lockscreen before using it though, as otherwise this will simply add a second lock screen on top of the one you have. If you run into issues, check out the XDA thread -- the developer has been really responsive to issues and questions, and odds are any problem you might have has been addressed in the thread. Hit the link below to grab it from Google Play or read more about it.