Find the perfect word
An exceptionally fine dictionary: the definitions are usually evocative and rich, and convey subtle nuances. (First example that comes to mind is the shades of meaning between swamp/bog/quagmire/morass/marsh.) The dictionary in some ways works as a thesaurus, and it’s great for finding the perfect word or phrase. Granted, most of the definitions are 100+ years out of date, but knowing the deeper context only increases your fluency. This is one of my go-to apps for reference & writing.
