This is not exactly a "web app", but for those teaching French, either in the core program or even Immersion, it's great to have good language models that kids can listen to. For teachers too, especially if you find yourself doing your own French, and you're not a French specialist! The site is called "IE Languages" and features audio from a number of European languages.
The French section (which interests me) has an extensive list of topics, verbs and expressions. While the emphasis is European, rather than Canadian, there's a lot of variety and could be very useful. Here's a listing from one of the units:
101. Camping
102. Special Uses of Devoir
103. Cosmetics / Toiletries
104. Medicine and Hospital
105. Present participle
106. Abbreviations / Slang
107. Past Infinitive
108. In the Ocean
109. To Die
110. In Space
111. Possessive Pronouns
112. Simple Past
113. Make-Believe / Fantasy
114. Religion
115. Music and Art
