Full disclosure: we make one of these (number 5). The first four are fair write-ups, and for plenty of people one of them will suit better than ours.
1. Language apps
Duolingo, Babbel, Busuu. Languages suit short daily lessons really well. They break down into thousands of small pieces, each one is either right or wrong, and repetition is how you pick them up. That’s why these are the most polished apps on the list.
Good for: vocabulary, recognition, and keeping a language ticking over.
Weak at: anything that isn’t a language, and real conversation. A long streak won’t mean you cope when you get there.
2. Book summaries
Blinkist, Shortform, getAbstract. Non-fiction boiled down to about 15 minutes. Handy for deciding which books to read in full, and for books that are one idea stretched over 300 pages.
Good for: getting through a lot, especially business and self-help.
Weak at: books where the detail is the point. You can end up able to name an idea without being able to use it. You’re also limited to books someone has already summarised.
3. Flashcards
Anki, RemNote, Quizlet. The best-evidenced option here. Spacing out your reviews is one of the most reliable findings in memory research, and these apps are built around it.
Good for: remembering facts you’ve already decided matter. Medical and law students swear by Anki.
Weak at: giving you something to learn in the first place. You bring the material, and writing good cards takes longer than you’d expect. Shared decks are hit and miss.
4. Skill courses
Brilliant, Sololearn, Mimo. Step-by-step courses in a fixed subject, usually maths, science or coding, where you do exercises instead of reading.
Good for: subjects where each lesson depends on the one before.
Weak at: anything outside their catalogue. They’re very good inside their subjects and have nothing outside them.
5. Ask-anything apps
Doomlearning, and a few others that use AI. You type a question and the app writes a course around it. These exist because the other four only help if someone has already made the thing you want.
Good for: specific or unusual questions that no publisher is going to make a course about.
Weak at: accuracy. AI writes the material and it does get things wrong, so check anything important elsewhere. Writing each course costs money, so free plans tend to be tighter than in apps with ready-made content.
Which one should you use?
Ask yourself whether a proper course on your subject already exists.
If it does, use the specialist. A language app will be better at Spanish, Anki will be better for anatomy, and Brilliant will be better at teaching you calculus.
If it doesn’t, that’s what number 5 is for. Here’s how Doomlearning builds a course.
The bit no app fixes
Whichever you pick, what matters most is coming back to it. Short sessions spread over several days beat one long session, and the best app is the one you still open next Tuesday. That’s down to habit more than software. Our guide to microlearning has more on what the research says.
We haven’t listed prices or feature counts because they change all the time. Check the app stores for current details.