Jobs should use the correct currency symbol to match your iPhone's country settings. No other setting is required to switch to € (Euro), ¥ (Japanese Yen), £ (British Pounds) or any other currency symbol.
The user interface is currently only in English. It's possible we'll add some other common languages in the future. However, you should be able to use any language when filling in the client name, job name, job notes or other fields.
Please get in touch if you notice something not working as it should for your currency or language.