@itsumonotakumi First of all, # has FAQ, which allows to search for answers and to ask new questions: https://github.com/andstatus/andstatus/wiki/FAQ
The change log lists features, added during the last six years, with links to detailed descriptions in corresponding development tickets: http://andstatus.org/changelog.html
Regarding concrete features, which are marked as missed. Just from the top of my mind:
1. Drafts: You can "Save draft" during editing (see a diskette icon above with this tooltip). Plus, AndStatus has "Drafts timeline" whist lists all drafts chronologically like in any email application. Any draft can be edited or discarded, naturally.
How this could be overlooked, if you specifically searched for this feature?
2. Timeline filters. There is more than one way to have filtered timeline:
2.1 Search for one or several words. Resulted filtered timeline can be even made syncable! (see Manage timelines menu item)
2.2. See "Filters" section in Settings.
Do you think that an interested User won't notice any of these ways to filter a Timeline?
... https://loadaverage.org/attachment/3744263