Mendeley for Mac provides an useful solution to document management. It has 1GB of free cloud-based storage which is also upgradable to 2GB for $5 per month, 5GB for $10, or $15 for unlimited storage. Mendeley for Mac comes with cross-platform compatibility and has a clear interface that is easy to view and navigate.
With Mendeley for Mac you can access your papers on the web or iOS device. Mendeley has mobile apps for iOS and Android platforms, allowing you to access your Mendeley library, read and annotate your PDFs, and keep everything in sync across all your devices.