Undelete Plus is simple and useful file recovery program. It is actively developed and often updated (like recent bump to 2.97) but home site lags behind and usually lacks details.
Program combines very fast scanning and decent recovery in the small and portable package. It is free to use but comes with small banners in the corner of interface so may be called adware.
I have to say that it belongs to "first-aid" recovery. It is good for instant reaction to freshly deleted file but complex cases require complex (commercial) tools or recovery services.
Home page http://undelete-plus.com/
Download page http://undelete-plus.com/download.html