Unarguably, learning a language is a complex procedure that requires a holistic effort (both cognitive and emotional). Since the 1970´s applied linguistics research, it has been argued that a language learner encounters difficulties that are strictly related to his emotional status and that may hinder the learning process (i.e. low self-esteem, learning helplessness due to the lack of clear learning goals, lack of motivation etc.). As a life-long language learner myself, in many cases I came across difficulties when learning a language that were less related to the difficulty of the language in itself and more affiliated to the feelings that I experienced when trying to learn things in an absolute formal way (i.e. through an only textbook) or even when imposed to learn to counter my willingness.
A great number of people make attempts to learn a language by using automatised ways with the assistance of apps and formal language exercises (multiple choice, drill and practice exercises etc.). There is a huge number of sites offering this also for free. However, in the author’s view, this does not promote long-lasting learning either does it enhance higher order thinking processes for achieving language reflexivity (or else the ability to think and feel in a foreign language).
When I was at the age of 4 I was so much stimulated to learn English when my father introduced it to me like a game by showing me some animals and asking me to say their names in English. My father was not a native English speaker but he loved languages and so this was transmitted to me, intriguing me to learn English at a very early age. Later on, in high school I had an English teacher that did not force me to do exercises (like any other teacher at school), she just made me love the language in her way...This kind of FREEDOM to learn a language at my pace filled me with a creative force that made me decide at an early age that I was to become a linguist. In fact, I have never stopped learning languages and reading their literature with great interest and discovering new identities (as a new language is similar to a new identity). It was also a way to get out of the rat race.
In order to achieve language reflexivity as the highest form of linguistic achievement, by using exclusively language apps and formal exercises without the in the flesh assistance of a language teacher and without a synchronous and structured exchange, might prove to be an unfeasible task. The teacher's role is decisive in effective learning as he/she becomes the bridge with the new language and culture.
Regarding online language learning
The online environment could prove to be ideal for informal learning and more adjustable to the learner's needs. Certainly, this could not be achieved in a formal school setting where a certain syllabus is already scheduled and everyone is obliged to follow it. And this is the magic of online learning. A number of different learners that are scatterred across the globe, coming from the most diverse backgrounds are a huge challenge for online educators. So an ideal online language learning setting should include synchronous and structured language interactions with an online teacher as well as authentic material coming from different technological modes (videos, texts, podcasts, quizzes etc.). Though, we definitely can not do away with an interaction with a real teacher in the flesh. As Earl W. Stevick successfully puts it "let the words, too, become flesh".