I know most people ignore the Samsung App's store, but it has a few useful apps in it.

The two I really like are:

For my Note II, there's an update to S-Voice.  Just search "S Voice" in there and download the updated version.  I expect this works for the S3 as well.  Maybe even the S2?  It seems have improved the recognition of my speech immensely, but it's also probably that it's just got better on the backend since I last used it.

Permission Manager is another great app.  Without requiring root, it can stop certain apps from access certain permissions.  i.e. you downloaded that Ringtones App but it wants to send SMS? You can stop it from being allowed to do that.

Other useful apps are "Polaris Office" and "Photo editor"

All these apps are Samsung Apps and free, and free of ads etc.

Just FYI in case someone else finds them useful.