RightFont 5

RightFont 5 is a great font management application for OSX(Mac) operating systems. Especially for the old ones, because it's so lightweight compared to its alternatives. Works fluently, has great features like;

• Syncing with Google Fonts, Adobe TypeKit.
• Easy and fast font preview in different modes.
• Easy to install and use in instant.
• It could use cloud storages as font directory so you can use your fonts in every device you own.

Reason I'm using it, just because it works better than its alternatives. Works smoothly on low specced mac computers. You can activate and deactivate fonts to speed up your design application run/open faster.

Only downside is only supports macs. It would be nice to have this tool on windows and linux too...

Screenshots from their website: source