I wrote an app that controls the Rdio desktop app running on my computer, which then streams through Bluetooth to Echo. It works well but I can't get Echo to understand "rdio" as a launch word. According to the FAQ, it's pronounced "r-dee-oh". I tried permutations like "arr dee oh" and "R D O" but nothing I tried worked. Is there any way to trick Echo into understanding weird words like that? Just curious, in the meantime I am using "music" as a generic launch word.
Since the Echo uses natural language processing, it will try to pick out words that make sense to it, so you're unlikely to be able to launch your app with "rdio" or "rdo". I would suggest picking an alternate launch word/phrase for your app. I'll also point out that making launch words or phrases have similar words to built-in Echo functionality, you're likely to have issues as you described where internal functionality is being called instead of your app being launched.
Hmm, Echo seems to be overzealous with its "play music" command as well. I renamed my launch word to "play" so I could say something like "Alexa, open play Radiohead" and have it play through my app instead of Prime but that doesn't seem to work - Echo doesn't realize I'm trying to open an app.