I've updated my Sublime-Evaluate plugin to be (hopefully) ST3 compatible. I had a weird problem with the edit stack becoming corrupt but I think I've fixed that now. It should also be backwards compatible, but please let me know if it doesn't work (I no longer use ST2).
Currently I'm waiting or it to be added to Package Control, but in the mean time you can get it on GitHub: Sublime Evaluate.
If there are any bugs, feel free to raise an issue or send a pull request.
Some things I want to add:
Improved Math, pi, atan etc
I may merge the SublimeWebColors
plugin to evaluate color codes into hex etc.