One of the coolest things about Android is the use of Widgets - the small "mini-apps" you add to your homescreen to get immediate information and functionality, often without even having to launch an app. Think of the weather ones, the fancy clocks, the stock price reporters or the RSS news feeds for example - they all update their displays without the user doing anything. There's clearly some magic going on behind the scenes here which may appear mysterious to the typical "app only" Android coder. 

Twitter recently dropped their REST API which meant developers had to adopt one of the new authentication methods to use their services. So, here's a combination of the two - a Widget which just sends tweets using the new OAuth Twitter API.

Have you ever thought hard about what you could do to your mobile phone to make it really useful? Something that solves an everyday problem you're so used to finding ways round you don't even think can be improved? I know with every smartphone I've had, there's always a few honeymoon weeks as I played the games, wowed at the screensavers and so on, but after that stopped using them because they're a battery drain, or just plain annoying, and then all I really wanted it for is to make life easier. So when a new app comes along which offers genuine usefulness it's a great feeling - a bonus beyond the initial phone purchase. CoolNote for Android is that kind of app, and all it really does (but does really well) is let you stick realistic looking notes on your phone, which, since they run as widgets, means no app launch is needed just to read them.