NXPowerLite will compress PDF, JPEG, PNG, TIFF, Microsoft PowerPoint and Word files simply and effectively, making them easy to email as attachments. It is especially effective on files that don’t zip well.

NetShred X is the easy-to-use Internet cache eraser for Mac that securely erases cache files your browser and email programs leave behind. NetShred X is the Internet privacy software that is easy, fast, and cleaner. Easy because it runs automatically - you don't have to remember to use it. Fast because it runs in the background - you don't have to wait for it. Cleaner because it will erase, not just delete all Internet tracks for almost every browser and email program on Mac.

Fission can crop and trim audio, paste in or join files, or just rapidly split one long file into many. It's streamlined for fast editing. Plus, it works without the quality loss caused by other editors, so you can get perfect quality audio even when editing MP3 and AAC files.
If you need to convert formats, Fission can do that too! You can rapidly export or batch convert files to the MP3, AAC, Apple Lossless, FLAC, AIFF, and WAV formats.