Anti-Features are flags packagers apply to apps, warning of possibly undesirable behaviour from the user's perspective, often serving the interest of the developer or a third party.
You will see these in the F-Droid client, and/or web repository browser when viewing the details of an app containing one or more of these Antifeatures:
- Ads (17 list) – advertising
- Tracking (31 list) – tracks and/or reports your activity to somewhere, even when it can be turned off
- Non-free Network Services (122 list) – promotes or depends entirely on a non-libre network service
- Non free Addons (20 list) – promotes other non-libre apps or plugins
- Non free Dependencies (32 list) – needs a non-libre app to work (e.g. Google Maps, Market)
- Upstream Non-free (104 list) – upstream source code is not libre, and this version has those parts replaced or rewritten
- Non-Free Assets (14 list) – non libre media in things that are not code (e.g. images, sound, music, 3D-models, or video)
- Known Vulnerability (2 list) – known security vulnerability
- Disabled Algorithm (0 list) – signed using an unsafe algorithm
- No Source Since (62 list) – source code no longer available, making new releases impossible
The numbers indicate how many apps in the main F-Droid repository have each antifeature, and you can click through to see them all. You can also see all apps with antifeatures (of which there are 363).