First you need a personal key. Create one via the menu in "Keys" or import existing secret keys. Afterwards, you can download your friends' keys or exchange them via QR Codes or NFC.
On Android lower 4.4, it is recommended that you install OI File Manager for enhanced file selection.
Please report the bug using the issue tracker of OpenKeychain.
If you want to help us developing OpenKeychain by contributing code follow our small guide on Github.
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