I have been using Pimsleur for about 2 years now, off and on. I started out with the Italian Level 1 and I enjoyed it so much that I purchased some of the Hindi, Korean, and also Thai lessons.
Pimsleur makes learning easy with their explanations, examples, fun and repetitive teaching - otherwise known as the Pimsleur Approach. Also, the cost of the lessons are quite inexpensive. And, some lessons come with reading practice which boost your vocab.
The only downside to Pimsleur is that there are not complete explanations on grammar use. For instance, in Italian Level 1: Lesson 24, there is no explanation as to why you use "parli" versus "parla". Both mean "you speak". It's my understanding that one is informal (parli) and the other is formal (parla). But, I had to do my own research to find that out. Also, flashcards and study vocab are not accessible on the mobile app - only on the desktop version. (This is why I gave it 5 stars instead of 4.)
In conclusion, this is an awesome learning tool but I would advise picking up a dictionary and grammar book to go with your studies in case you have any questions on vocab that Pimsleur does not cover.
Update: 8/8/21
I'm still using Pimsleur. In fact, I'm about to finish Italian Level 2. (Truth be told, I would have already finished this level a long time ago, but life got in the way. I changed jobs and also studied Hindi for a while before deciding to go back and continue my Italian language study.)
This program is still one of the best out there. Pimsleur uses word repetition, word building, and native speakers to help you learn words fast and remember them long-term. For instance, every Pimsleur lesson begins with introducing new words for around 5 mins. Next, you start to repeat the material for 10 minutes. Then you build on that with more words to expand the conversation for 5 more minutes, then another review for 10 minutes. Each lesson is broken down into segments to introduce words, review them, introduce more words, and then review them. Some lesson times may vary, but this is the basic structure of every lesson.
As I progressed along, I have found that more grammar explanations have been made; but I do think that the explanation of some grammar usage could be expanded on - if not in the audio, then maybe in a supplemental that comes with the lesson.
I previously stated before that there were not review flashcards on the mobile version. Well it turns out that it depends on the type of phone that you use. I was using a medium-end smart phone when I started using Pimsleur, but now have upgraded to a high-end phone (Samsung Note 20) and I have access to all the features now and they do have flashcards. So, that was simply an issue with me not using a better phone. Although, flashcards were always available on their website, so it's not like I was missing out.
So, if you've ever had trouble learning a foreign language, give Pimsleur a try. Right now, the first lesson is free. Just create a free Pimsleur account, log in, and choose the language that you're interested in. Again, the first lesson is free so your can't go wrong.