I've made a con-script called Sprykski, for the videogame Spryke. It contains 52 letters, and be used to write English, and most Slavic languages, among others.
It's my first con-script. I really enjoyed the process, so as I keep working on Spryke, I may end up making more con-scripts for other races/nations in Spryke's universe.
Let me know what you think. You can read more about the design process behind Sprykski here: http://www.volnaiskra.com/devblog/designing-an-alien-alphabet