I am developing a simple android app, I want to use file picker when I press button, so how can I implement file picker in my app.
I spent some time earlier figuring this out so to wrap up
Intents provide the ability to hook into third-party app components for content selection. This works well for media files, but if you want users to be able to select any file, they must have an existing "file explorer" app installed. Because many Android devices don't have stock File Explorers, the developer must often instruct the user to install one, or build one, themselves. aFileChooser solves this issue.
You can clone it from iPaulPro/aFileChooser.