Utility activities?
<p>I'm a little confused about the naming conventions used here... but AFAIK it is possible to build an activity(?) that performs some small function than many different programs could use. For example a date-picker tool for use in a calendar or alarm program.</p>

<p>Fist of all I wish to know what these things are called. Where can I see a list of common ones that people expect on their phones pre-installed. And finally is it possible to make and distribute your own?</p>

<p>I had initially thought these things may be called widgets, but having had a look at a few of them, they appear to be complete programs in their own right - so I'm assuming that widget is not the word I'm looking for.</p>
