I've played Quell and Quell Reflect. Is there more?

Yes, Quell Memento.is the third title in the series, and is currently being released across multiple platforms:

Now - iOS Appstore (published by Bulkypix)
May 28 - PS Vita Store (EU)
June 2 - Amazon Appstore
June 4 - PS Vita Store (US)
June 29 - Google Play
June 29 - Nook Apps