Chronological order ✓
You can display by creation date or update date (I think the latter is the default). The webapp has some more options than the Android application.
Display as a timeline ✓
The notes (title, excerpts and pictures (pictures can be deactivated in settings)) are displayed in the selected order on the left. The selected note is displayed in full on the right side.
On an Android phone, the view switches between the timeline and the selected note. On a tablet, you can have both columns as on the webapp.
Support for tags ✓
Two hierarchy levels: notebooks and tags. You may use one or the other, or both. Everything is up to you.
Notebooks are like files or folders: each note can belong to only one.
Tags are like color post-it: you can add as many as you want to a note.
Both in webapp and Android app, though less performant with complex queries in the latter (the example I used in the webapp returned nothing in Android).
Multiple media for notes in Android app ✓
- Text ✓
- Audio: via attachment; speech recognition is not integrated but I guess you can combine with a dedicated app
- Photos/videos ✓
A simple UI
This will be left to the appreciation of each.
With great functionality comes more complicated interface.
What takes the most time getting used to (I'd say ten minutes at most) is the navigation, as you have much more sorting options than Google Keep where all notes are loose in the same place.