Instead of using the ContentProviders of each app, the Dev proposed to use the an startActivityForResult() to start the other apps to process data and then set the result on the setResult(Bundle) method of each Activity triggered.
If by "to start the other apps to process data", you mean "to show an activity to the user, to allow the user to interact with data", then using an activity is perfectly reasonable. Having that activity return a result is also reasonable, if the point behind the activity is for the user to pick something.
If, however, by "to start the other apps to process data", you literally mean that the other app is not going to be displaying anything, but is just going to "process data" to return a result, then an activity is a ridiculous choice. Whether a ContentProvider
is a better approach than is a Service
would depend a bit upon what "process data" means and what sort of results are being returned, but either would be preferable to using an activity.