Google Docs has a feature to see the difference between two documents and can show them in a new document. This is entirely different from seeing the “document history” (version) feature.

Google Docs has a feature to see the difference between two documents and can show them in a new document. This is entirely different from seeing the “document history” (version) feature.
Task Management (including Projects and Goals Management) – consider financial management as a project inside this.
Time Management (events to attend, meetings)
Notes Management / Ideas, PKM (Personal Knowledge Management) / Minutes / Journaling (including physical notes).
Files Management (including physical resources), Document management.
Communication – Email Management, People/Contacts Management
What are the apps you use for each scope?
P.S. 4 Steps to write an efficient memo (1) Write/draft your instructions as action-steps, (2) Rewrite them for utmost clarity and simplicity, (3) Rephrase the sentences to make every step unambiguous and connected (adopt 3rd person's view or ask for feedback, if needed), and (4) Repeat steps (2) and (3) until you make the instructions as short as possible.
Remember. Your notes should be self-sufficient. A well-written note should avoid the necessity of referring back to the source and references.