There's a little voyeurism in all of us I guess but this takes intelligent spying to another level. DailyScreenshot is a free app that literally keeps a full sized screenshot of every single website every single day. Imagine how easy it is to keep a track of your business competitors, online newspapers or even your partners. You can also use it to archive and curate your own website over the year and analyze how you have developed.
DailyScreenshot is oh-so-easy to use. Just type in the URL's you wish to track into the box and they will do the rest. You can capture the subtle design and user interface choices that are not saved in RSS aggregator feeds. Alternatively, you can follow exactly where and how you appear in search queries in any search engine.
Whether using DailyScreenshot for moral or immoral reasons you can't deny it's efficiency. It does everything it says it will do and more. These days, modern business is a cutthroat affair and anything you can do to get ahead of the opposition has got to be beneficial to you. If used intelligently you will always be ahead of your competitors. However, if you're thinking of using it as a way of tracking your partner's night time habits you might want to call a marriage councellor first.