It's doesn't have a UI, but I wrote a command line tool called Overcast that lets you create/manage/destroy/reboot DigitalOcean and Linode VMs. Support for AWS is on the roadmap. http://andrewchilds.github.io/overcast

    # Create a new Ubuntu 14.04 instance on DigitalOcean
    $ overcast digitalocean create db_01 --cluster db

    # Create a new Ubuntu 14.04 instance on Linode
    $ overcast linode create db_02 --cluster db

    # Configure both instances in parallel
    $ overcast run db install/core install/redis --parallel
    $ overcast expose db 22 6379 --parallel

    # Interact with both instances at once over SSH
    $ overcast ssh db

    # Reboot, snapshot, destroy, etc
    $ overcast digitalocean snapshot db_01 db_01_snapshot
    $ overcast digitalocean reboot db_01
    $ overcast linode destroy db_02

A while ago I wrote a CLI tool that does exactly that: https://github.com/ema/nubo

The tool also exposes its functionalities as a python library, so it might be useful for those who want to manage their VMs through a panel indicator.

And if it supported the monitoring services for Cloud providers. Looks like I found a new weekend project!