The Arsse does not at this time have any first party clients. However, because The Arsse supports other protocols, most clients built for NextCloud News and Tiny Tiny RSS are compatible with The Arsse. Below are a few that we personally know of and have tested with The Arsse.
Name OS Protocol Notes
Nextcloud News Tiny Tiny RSS Fever
Desktop
FeedReader Linux ✔ ✔ ✘

Excellent reader; one of the best on any platform.

Not compatible with HTTP authentication when using TT-RSS.
FeedTheMonkey Linux ✘ ✔ ✘

Newsboat Linux, macOS ✔ ✔ ✘

Terminal-based client.
ReadKit macOS ✘ ✘ ✔

Requires purchase.
Reeder macOS ✘ ✘ ✔

Also available for iOS.
RSS Guard Windows, macOS, Linux ✔ ✔ ✘

Very basic client; now discontinued.
Tiny Tiny RSS Reader Windows ✘ ✔ ✘

Does not deal well with expired sessions; discontinued.
Mobile
CloudNews iOS ✔ ✘ ✘

Very bland looking application, but it functions well.
FeedMe Android ✘ ✔ ✘

Not compatible with HTTP authentication.
Fiery Feeds iOS ✘ ✔ ✔

Rentalware - For the software to be usable (you can't even add feeds otherwise) a subscription fee must be paid.

Currently keeps showing items in the unread badge which have already been read.
Newsout Android, iOS ✔ ✘ ✘

iOS version only as source code.
NextCloud News Android ✔ ✘ ✘

Official Android client for NextCloud News.
OCReader Android ✔ ✘ ✘
Readably Android ✘ ✘ ✔
Reeder iOS ✘ ✘ ✔

Also available for macOS.
Tiny Tiny RSS Android ✘ ✔ ✘

Official Android client for Tiny Tiny RSS.
TTRSS-Reader Android ✘ ✔ ✘

Unread iOS ✘ ✘ ✔

Trialware with one-time purchase.
## Known Incompatible Clients
Name OS Protocol Notes
Nextcloud News Tiny Tiny RSS Fever
tiny Reader RSS iOS ✘ ✔ ✘

Does not support HTTP authentication.