Pretty much stole the words from my mouth. Kids are also better able to differentiate between sounds, while adults might struggle with certain words of a foreign language because their brains tune out sounds that don't fit with their dominant language.
Not to say you are wrong, though. Being proactive definitely helps in mastering any language. I know because when my mother first immigrated to America, she had to learn Cantonese fast to communicate with her coworkers. She would tell me that she didn't care if she mispronounced a word; she would just speak and get her point across until someone corrected her. I would say that she is pretty fluent now as a result.
I think I have a more pessimistic view when it comes to learning languages through apps. They are certainly good supplementary aids, but only if you are already learning the language through a more traditional means. Personally, I need an instructor to physically be there to correct my mistakes and motivate me to work harder. With apps, the responses aren't as immediate and I retain less of the information if I'm not being pressured by a grade.
But if getting a language teacher isn't an option, I would much rather recommend a language learning site over an app. I am currently taking Korean in school, but prior to that I self-studied using www.howtostudykorean.com and I can honestly say it has helped. I can barely say the same for some of the language apps I used like Hellotalk.