Honestly I missed Calculator.app along with Mail.app on Linux quite a lot! I settled with Qalculate - it can do some things as Spotlight (currency conversion)

Honestly I missed Calculator.app along with Mail.app on Linux quite a lot! I settled with Qalculate - it can do some things as Spotlight (currency conversion) and also quite nice for programmer-related tasks. Although I miss few features here and there it is quite good.