As a developer changes code (provided he uses version control), s/he can compare new code to old to see what changes were made over two "points in time" (or versions).
What might be more convenient for some scenarios is an IDE add-in (extension, or whatchamacallit) that would record all changes in this manner:
11:39:42 Changed "Activity1" to "MainActivity"
11:42:27 Added a new layout named "Whatchamacallem_TheBand.axml"
(etc.)
Is there such a beast? If not, why not? It seems it could come in handy for many scenarios - helping you remember what you did on a certain day/edit session (perhaps to make meaningful/accurate checkin comments), in writing tutorials so that "minor" but necessary steps are not omitted, etc.
UPDATE
ISTM that even a subset of this would be a very handy "solution diary", in that it could contain such items as:
On 3/14/2014, installed "Microsoft Http Client Libraries" version [was.auch.immer]" via NuGet
On 3/26/2014, installed "Windows Mobile Services" version [sea.lo.que.sea]" via NuGet
Maybe such an auditing tool could then be queried by filters such as "NuGet" or so.
UPDATE 2
Drodio (Android Studio) does have a minimal implementation of this, via its View > Recent Changes window:
UPDATE 3
The more I use Droidio, the more I like it; from the editor, access the context menu and select Local History > Show History. Now this is more like it/what I'm talkin' about: