Sadly, some things get blocked for the Arc in Google Play, likely because of its lack of a GPS.
espace.mu probably uses Flash, which isn't supported on the Arc, though there are other posts here with the links to download a working version (I'm too lazy to look 'em up for you :P).
If you can find TuneIn Radio from an alternate source it should work perfectly fine (the version from
Good E-Reader works great for me, but they are having some severe site problems this weekend, so you might need to wait a few days to get it; I'd direct download, though, as I found their store app to be a complete mess that crashed regularly).