Please note that this article solely represents the opinion of the author
In recent years, the number of apps and programs designed to teach a language to whomever is willing to dedicate the time has grown exponentially. Whereas even 10 years ago Rosetta Stone was the only available program, and fairly pricey at that, now language learners can get Duolingo for free, Transparent Language, and countless other programs designed to get them learning a new language, for fun, business, or whatever the reason may be.
As you may or may not know, in addition to being a language teacher by day, I am also completing a certificate in educational technology through Johns Hopkins University, and I have found in the past few years that language learning with technology is becoming my specialty. In a classroom, this means using Google Maps, looking at authentic websites, or having e-pals over Skype, but I understand that for many adults or other learners outside of a traditional program, these apps and programs are what represent language learning technology.
But do they actually work? The question is a difficult one. My personal answer is the same I would give to any student or teacher who asked about using technology; any technology is simply a tool to facilitate learning. The program itself is not going to make you a proficient speaker; rather, it is a tool to practice grammar, vocabulary, reading, etc., that will enable you to go out and practice your language with other speakers.
One of the major improvements in the past few years has been contextualizing the learning; Duolingo in particular has made some fantastic strides in this area with its reactive text writing activity, and almost all of the major programs now offer conversations to be read or listened to so that learners can actually see how language is used in a daily context. Many programs are still unable to provide authentic speaking, but as the technology improves, I expect this to be a potential new source of practice.
In short, these programs are not a replacement for actual communication. Instead, they should be seen as another tool, much like any teacher would use. Do not expect to become fluent by using Duolingo 20 minutes a day, but use it to gain the vocabulary and become comfortable with the language, and then actually go out and practice with native speakers, or even those who know it as a second language. As any language teacher will tell you, “learning” a language only goes so far until you actually begin communicating. While being in a classroom with a teacher is still the best method to gain a foundation, these apps can provide the service where a class is not available or affordable. Yet at the end of the day, unless the learner actually gets out in the world and practices the language, they will not have truly learned it.