Bitcoinproof creates a forgery-proof timestamp for your data, secured by the Bitcoin network. It allows you to prove that a certain event happened before a certain point in time. Maybe you want to prove that the damage in your flat already existed when you moved in, or that you were in possession of a great artwork before it was published, proving you are the author.
Chrome Page Notes lets you take notes for Web pages as you visit them and access these notes later when you visit those Web pages again. It provides visual cues to let you know if there are notes available for the Web page that you're on. You can choose to sync your notes automatically to your Google Docs account. You can configure multiple computers to sync to the same account, and thus keep your page notes synced across multiple computers.
Eco-Memory is the classic memory game where the goal is to find matching pairs of cards. The cards represent habitats, organisms, and cultural entities of ecosystems like the Boreal Forest, Coral Reef, Deciduous Forest, Desert, Ice, Intertidal Zone, Rainforest, Surface Zone, Tundra, and Wetland. The game includes a small synopsis of the organisms, the cultural entities, and the habitats themselves. The synopsis is available through an "About" button that you may click after finding a matching pair of cards.