SmartClient by Celigo, Inc this is a heck of a free app. If you are an Office 365 (online) user, you will love it. Install the add in app into Excel 365 and you are able to load any of the Salesforce data you select. The power is that you are able to edit your field values in the spreadsheet and simply click “update”, which commits the changes to Salesforce.
If you do a lot of data loader work this in my opinion is a must have! Try it, you will like it.