Develop Reference

How to programatically restart another android app?

Firstly, I understand that commonly this is not something that you typically want to do. However, the app I'm developing adds functionality to another app, but requires that the other app be restarted for it to work.
Is it possible to restart another app (i.e. -> user clicks a confirm button, other app is closed and reopened)? How would I accomplish this?
If it's not possible normally, would it be possible if the app has SU? How would it be accomplished then?

I found a way that no need root permission.
ComponentName componentName = getPackageManager().getLaunchIntentForPackage("com.xxx.yyy.zzz").getComponent();
Intent intent = IntentCompat.makeRestartActivityTask(componentName);
startActivity(intent);

There are some ways to interact with other apps through Android. Usually, intents are used for this.
You can go through this tutorial that shows what are the possible things you can do with other apps using your activity.
Especially, see the Lesson: Sending the User to Another App

I was able to uncover an answer... hopefully this will be helpful to those of you looking for the same.
Using RootTools, this is very easily done.
RootTools.killProcess(package);
Intent LaunchIntent = getPackageManager().getLaunchIntentForPackage(package);
startActivity(LaunchIntent);

How to configure the android intent actions in android manifest

I have a webview in my app, on trying to do actions like making a call (Tapping call button from results displayed in webview), sending mails and other actions, my webview doesn't perform those actions
I Found a solution to add the intent actions in my web view activity as
Intent intent = new Intent(Intent.ACTION_DIAL, Uri.parse(url));
startActivity(intent)
Instead of doing so is there any way to add in the android manifest file
or Is there any way to turn on all of the intent actions for the webview so that
there wont be further issues in handling the actions
Can someone help me on this pls

Your answer seems to me a bit strange, I think you are a bit confuse about the difference between Intent and manifest permission. The first one are the system used by android to let app communicate with each other, the second one allow you to use some feature of the device like wifi and direct phone call that need the explicit agreement of the user to be used (the prompt that popup when you make the first install of an app).
With this clarification it is clear that if you want to do something that require another app you will have to make an Intent. This Intent, if well formed, will be elaborated by the os that will take care of sending it to the correct application able to accomplish the Intentrequirement.
So the answer to your question, as far as i know, is no, you have to use intent if you have the need of calling external app. It's also a good practice to set in the manifest only the permission really needed by the app, this way the user know what the app really can do and and what it can't do.
Hope i understand your question and answer it.

notify installation complete from service

I have this piece of code
private void initiateInstallation() {
Intent intent = new Intent(Intent.ACTION_VIEW);
Uri uri = Uri.fromFile(new File("/sdcard/example.apk"));
intent.setDataAndType(uri, "application/vnd.android.package-archive");
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
that from within my service installs an application named example.apk
I want after the installation is finished to run an activity which notifies the user about the installation.I did that except the activity appears before the installation finishes.
The problem is that within a service I cannot use startActivityForResult. So, I need a way around this so that I can start my notification activity(or for the sake of example just print something out with Toast within the service) only AFTER the installation is complete.
I already tried some answers from other questions like "alternative to startActivityforResult in services" but still I couldn't figure this out.
I also put the code so that maybe there may be something done in there.
Thanks in advance ... any suggestions are welcome.

You could listen to the PACKAGE_ADDED broadcast intent: http://developer.android.com/reference/android/content/Intent.html#ACTION_PACKAGE_ADDED
As far as I know, these are sent after the installation is done, and you can listen to those from the service.
Just note that if the application was already installed, you will get ACTION_PACKAGE_CHANGED (as far as I know).
Also you must know the package name as well, not just the apk name, since the intent will contain the package name.

The answer given by #Pal Szasz is technically correct (as far as I know ;-) ).
However, based on the information given in your question, I assume you only wish to show a notification (no further programmatically actions are to be performed). If my assumptions are correct I would respectfully advise you NOT to show such a notification. And this is why:
The Android system already has a standard means of passing notifications to the user. The status bar will in this case already show you a message saying that the new app is successfully installed (or not installed in case of an error). If you implement yet another notification channel you will most likely confuse or irritate your users by diverging from the standard, expected behaviour.
Taking this beyond the borders of sanity one could also argue for the fact that you in some sense also would contribute to the fragmentation of Android (in a very small scale, but nevertheless).

accessing one app from another app

Can someone explain me how to control one application from another application? I'm running a music player in an app1 using service class. And I want to stop that music player from another app.,i.e app2. But, I'm fallin short o the concept.

Depends what you need to do.
Opening another activity (or sending messages) is by using Intents:
Intent intent = new Intent();
intent.setAction(android.content.Intent.ACTION_VIEW);
// ...
startActivity(intent);
Starting service is by using startService()
What you are trying to do can also be done using Intent broadcasts but only if your target app supports and listens to specific actions on the broadcast. You need to see if there is such an ACTION supported.

I'd like to continue this question a bit.
In my case, I'm developing the target app and I need to implement few simple procedure calls for the main app. Basically 'start', 'stop' and 'sendData'. As I wrote, I'm developing the target app so I can support whatever I want. Which would you say is the easiest way to handle.
The whole situation a bit more explained. Main app would like my app to start it's work, and if needed they'll request that I turn myself off and when the main app is closing it would request me to send my data forward.
I'm quite new to android development, so code snippets are preferable. Thank you.

Android: Proper way to reuse my app's activities?

What's the proper way for other people to reuse my Activities? Should they hard code the intent actions in their app or is it customary to provide them with a jar file enumerating my app's intent actions? Is there a less tightly-coupled way to lookup the intent actions?

First of all, take a look at openintents.org and see if there's any match to what your activity does.
Secondly, documentation is always a good idea.
Having the intent details hardcoded in their applications should work just fine. After all, the intents are part of your public interface and shouldn't change.

Your applications manifest should announce what sorts of things your activity can handle, via intent-filters. Outside users can read the manifest to determine what actions you support, and invoke them via action intents.
See intents and intent filters for more details.