For most academics, citations are a critical part of writing. Scrivener is fairly well served if you are using Bookends as it has a native floating citation picker; and Zotero also has some citation pickers. But there is a brilliant new citation picker for Alfred that uses a BibTeX file and outputs Markdown citations, meaning it should work with many good Reference Managers (Bookends, Zotero, JabRef, BibDesk), and as it uses the BibTeX file doesn’t need any app open and works in any writing software:
It is super fast, giving many option for working with your citations. It also includes other tools like a CSL search engine, backup and other functions. Well worth contemplating for your academic markdown workflow!