Android: Friday, a new personal assistant app for Android that keeps an eye on the things you do with your Android phone, collects and organises them into a database, and then uses that database to help you make smart decisions about who you call, where you go, and how you spend your time. You can ask Friday questions about your own life and activities, and Friday will have the answers for you.
Friday is brand new and in beta, so expect some kinks. The tool is designed to give you a set of "personal analytics", which really means the app can answer questions like "how long does my commute take?" or "When was the last time I called my mother?" with absolute accuracy, because it knows how long it takes you to drive home, and it already knows the last time you called your mother (and how frequently you call).
While Friday wants to use all of this data to build a kind of "Personal Wikipedia", it's not just about organising useful information. The service's "Applets" feature allows third party developers to build plug-ins for the app that will proactively help you use the information. For example, if you tend to spend a lot of time streaming via 3G, a developer could build an applet to find you nearby Wi-Fi networks in the places you normally stream music. Right now, the only applet available is one that automatically builds an interactive map of the places you travel and how long it takes you to get from place to place, but the developers behind Friday say more are on the way.
The Friday beta is open now, and you can download the app directly from Friday's site or from Google Play. If you're looking for a way to quantify your day-to-day activities, and ever wished you could do a search of your own life and habits, this is an app worth looking into.