I just wanted to give a shoutout to Langify. I've tried all available translation apps in the Shopify store and Langify is the best due to the following three things: 1. easy/list-based translations (the theme translations go reaaaally quick)
2. Really good auto-insertion of the translation tags (no coding neccessary)
3. both the original and translated versions can be mapped to subdomains and will be indexed by Google (with a link to the correct page). This is awesome stuff!
On top Johannes provides truly exceptional support!