Mind Body Store
Great app for controlling shipping costs and in my opinion, better than 'Better Shipping' which doesn't provide any per variant shipping options.
I did run into a problem when downgrading my shopify account, as this removes Real Time Carrier Shipping automatically, so the app stopped working until I got this added on again by shopify support. eComShipper Support helped to identify this problem, although it took a little while. Support could be quicker / more responsive.
Being a new app, there is still some room for improvement, such as Shipping Zones - currently each country needs to be entered individually, instead of being able to enter, say "Europe" and then select which countries within Europe should be included. It would be great to see more user, time-saving friendly features.
All in all, well worth getting.