This section is about the Welsh language, and in particular some resources to help people learn the language. For example there are online dictionaries such as Geiriadur.net ("Geiriadur" is Welsh for "dictionary"), online learning courses like saysomethinginwelsh.com, the TV channel S4C and the BBC's content at BBC Wales and Radio Cymru. Depending on where you are in the world, some of this BBC content may be blocked, unfortunately. The Wikibook on Welsh is a great introductory guide too. Clwb Malu Cachu looks like it hasn't been active lately but it's still got some excellent resources.
As with the other vocab testers, this one is the same but for the Welsh language. Again you get questions in both directions, but there's an extra feature here - the vocabulary is split into three groups, so you can start off with the "easy" version, with a smaller number of words, and once you're comfortable with that then you can proceed to the medium and advanced versions.
Several years ago, the BBC had a course for learning Welsh called "Catchphrase", which is now "archived and no longer updated". Here at the Activity Workshop, with the BBC's permission, we're starting to offer some additional material to go along with the BBC's. See the Catchphrase page for links, lesson summaries and subtitles for the audio.
There is also a dictionary which lets you look up words in English or in Welsh, shows you the translations, and also shows in which of the BBC's lessons those words appear.