There's now a Party Chat troubleshooter, links to Game Hubs from Achievements, Achievement descriptions in the notifications, and an updated "What's On" feature allowing you to keep up with trending content that may be to your liking.
Here's a video detailing the new features:
ORIGINAL STORY 23/03/2015: The Xbox One's April system update includes further improvements for the console's party chat and achievement apps, Microsoft has detailed.
But these make up just the first half of April's update, which Microsoft is releasing to preview programme members in two waves.
Party chat now includes a troubleshooter to make sure users' microphones are enabled, and to show when privacy settings or network issues are blocking chat with others in your party.
Meanwhile, achievement notifications now include the award's description text, so you can see what you did to unlock it without having to switch to the app.
The achievement notification's speed has also been improved, meaning that it hovers around on your screen for far less time.
And there's further integration of the Xbox One's recent game hubs feature, which will now be linked to from the achievements app and in your feed.
Xbox One preview programme members have received these features already, but they should be released generally around the start of next month.
Microsoft is set to detail its second wave of April update features next week.