I would like an application which is not readily apparent to casual perusal of the Android.
How best to activate it and bring its screen to the fore? Can I detect a special dialing sequence, like *1234#? Or a hotkey combination?
When activated, I guess I can pop up an anonymous screen which does not mention the app, but only asks for a password.
If password is ok, then show the app.
Any suggestions?
If you're simply trying to hide some type of functionality you could mask the application with something very simple like an app that showed a slide show. You could then listen to key presses or gestures in the mask app and launch the required functionality or application.
Also you could use a service which listens to all sorts of interesting things. If you ran a background service which listened to incoming sms you could start your application by texting yourself a certain code.
a service could also listen for key presses which are not handled by the top level activity.
There are many ways to do this I suppose though the simple masking app is likely the easiest.
An extended reply to tstenner's comment.
You can implement a BroadcastReceiver which listens to the Intent 'android.intent.action.NEW_OUTGOING_CALL'. Check the docs for more info!
Do not, however, that your application will still be visible in the package manager, as it should be.