This application is a joke. It might be useful if you never needed to say any number over 10 (but at 8500 Kip to the US dollar, just getting to 10 won't help you buy anything), or mention any day other than today or tomorrow, but in the real world, the limited vocabulary will leave you frustrated.
Then there's the problem of pronunciation. Since it does not provide the tone marks, your chances of being understood are close to nil. Neither can you show your screen to the person you're trying to speak with, because this application does not provide the translations written in Lao.
It took me almost a half hour to download this app (connectivity is very bad in Laos) and it was a complete waste of time. Why do they even bother?