The LowPowerLab RFM69 and SPIFlash libraries are now published to the Arduino Library directory, and available to install in the IDE’s Library Manager (under Tools>Manage Libraries). Note that if you already have these library installed manually, you may need to remove it and re-install using the manager:
As new versions are released, you can update to the latest or switch back to an older version if you have a need to do so. If you’re new to using the Library Manager, it’s worth to read the official Arduino Library guide, and also check the Library Manager FAQ, to understand how Arduino libraries work, and how manage them (adding, switching, updating, manual library installation, deleting local libraries, etc).
As usual, please report any issues or bugs in the forum or open a Github issue where appropriate.