Tips
Applications
Allow your activities to be added to the current task
For this behavior, your activity should have a launch mode of standard or
singleTop rather than singleTask or singleInstance. These modes
also enable multiple instances of your activity to be run.
Main
To launch your main activity from an icon at Home, the activity needs to have
an intent filter with action MAIN and category LAUNCHER).
Intents
Can I use this Intent?
Filter
When writing an activity that won’t be re-used, don’t specify intent filters - use explicit intents:
If you’re writing an activity that you don’t want other activities to use, be sure not to add any intent filters to that activity. This applies to an activity that will be launched only from the application launcher or from other activities inside your application. Instead, just create intents specifying the explicit component to launch - that is, explicit intents. In this case, there’s just no need for intent filters. Intent filters are published to all other applications, so if you make an intent filter, what you’re doing is publishing access to your activity, which means you can cause unintentional security holes.
Re-use
When reusing an activity owned by others, handle the case where no activity matches…
Notifications
Use the notification system - don’t use dialog boxes in place of notifications: If your background service needs to notify a user, use the standard notification system - don’t use a dialog or toast to notify them.
Layout
If you are having trouble with a component consider wrapping it in a layout. I used this technique to help me apply animations to an image view control.