AUDIO-VIDEO-MEDIA

AUDACITY (Windows, Mac, Linux)
A superb audio recording and editing app. I use it for all my audio recording and processing - don't waste your money on commercial products.
The default file format is Audacity (suffix .aup) that is used for all editing functions, from which selections can be exported into several formats
such as mp3. Other nice features include: (i) you can select a piece of background noise and subtract it from the entire file; (ii) there are several
 (programmable) options such as click removal, equalization (with several pre-defined settings such as "am radio"), setting maximum amplitude for
all files.  I have had satisfactory results using all default settings. I have a glitch in my Linux Mint version (no sound when recording but this
might be a quirk of my setup) although the Windows 7 version seems fine. It  crashes occasionally and I have found one silly quirk: when exporting
 to a format such as mp3 the file extension is not automatically ".mp3". The homesite is HERE

GOOGLE PHOTOS
This is the successor of  Google Picasa.

GIMP (Gnu Image Manipulation Program).
Windows Link - it is a part of probably most Linux distributions. Evidently comparable with Photoshop in sophistication (I have only used its
simplest features). Cheat Sheet HERE

VLC MEDIA PLAYER   (Windows, Linux)
Best of the bunch. I believe Microsoft now defaults to this.