Project description
https://tools.wmflabs.org/crosswatch is a cross-wiki watchlist for all WikiMedia wikis. The goal of the project is to help editors who are active in several wikis to monitor changes and generally to provide a better watchlist for all editors. Among other things, crosswatch includes cross-wiki notifications, dynamic filtering and the ability to show diffs for edits.

As an external tool which uses OAuth to retrieve the watchlists on behalf of the user, it doesn't have the same constraints as MediaWiki and can experiment with the design and functionality of a watchlist without breaking existing workflows or code. It's design is much more similar to the mobile watchlist than classical MediaWiki watchlist layout, there is however an option to use the traditional layout. Crosswatch can show a unified watchlist for all wikis or a watchlist subdivided into wikis.

One of the predominant features which users used to the MediaWiki watchlist will notice is the native support to show a diff for an edit. The diff will be shown if the user clicks on a watchlist entry or automatically if specific criteria are met. Currently, automatic diffs are show if the edit is unreviewed (for wikis wich use the FlaggedRevs extension), or if ORES predicts a revert.

Missing features and known bugs
See crosswatch for a full list of missing features and known bugs. To list a few features which the MediaWiki has but crosswatch hasn't:

• T108000: Visual collisions in mobile view (Chrome, iOS) – crosswatch is currently not optimized for mobile which results in some visual collisions and bad performance.
• T109200: Mark links in red colour, when page don't exists – redlinks are currently not shown, mainly for performance and stability reasons.
• T107844: Incorporate site announcements – site/watchlist announcement are currently not shown as there is no trivial way to implement it.
• T104608: Add support for absolute time instead of relative time – often requested, main problem is adding the day changes subheaders for the unified watchlist

There are also many feature wishes for crosswatch, a limited selection:

• T107836: Option to mute page, user or talk page section – would be very nice, e.g. hide a currently very active page for 5 days from the watchlist
• T108476: Live update – main problem is not to cause inadvertently scrolling
• T107736: Collapsible filter/preferences section – often requested, currently not implemented due to upstream bugs and the difficulty to do incorporate it with the framework
• T100158: Allow watching cross-language page clusters – so that users could watch their favorite article in all languages for changes

Weblink : https://tools.wmflabs.org/crosswatch
Resource links: Documentation on Meta, source code

I want thank my mentors @yuvipanda and @Legoktm for helping me throughout the project. Special thanks to @KasiaWMDE and @Bmueller for helping to spread the word and making crosswatch better known.