Updated:Great app, what I was referring to before is a feature I found out you can disable when you want. That way you can practice without distractions first and then add them in for another level of difficulty. Brilliant! 5 starsPrevious review:I’m using the iPhone SE and for some reason the app will click itself randomly during a session even if I don’t have my fingers near the screen. Sometimes it clicks itself once here and there, other times it will do so for five turns straight. Obviously, this breaks my concentration and I cancel out of the session. This is frustrating when trying to level up since you are so focused on memorizing more than you are used to and then having to deal with this particular bug throws a huge wrench in the whole experience. If this bug were fixed, I’d pay for the app.

I love this app. It’s ease of use is a bonus. Initially, I didn’t know how to play but easily found all settings and detailed instructions/videos in the profile section. I’ve noticed a vast improvement in my working memory since beginning this app. I’ve tried other Dual N-Back apps but none compare. I’m grateful.

The core gameplay itself is solid and I have no complaints there. However, several of the surrounding features are buggy or poorly implemented:(1) The daily average score and level charts seem to use an exponential moving average with a weight of 0.5 rather than a simple mean. This means that if you score 100% on 9 games followed by 0% on one game, your “daily average” will be 50% rather than 90%.(2) The automatic level adjustment option specifies “fallback grace: 1”. I assume this means that if you do poorly for just one round, it won’t immediately level you down. Either I don’t understand what this feature means or the implementation is broken because I always get leveled down after getting 50% or less on a single round.(3) This is a bit more subjective, but game duration is specified in seconds rather than total match opportunities. This means that at level N=2, the default options (60 second duration and 2 seconds in between each square/sound) will give you 28 matching opportunities per game (out of the 30 shown). However, at N=10, you only have 20 matching opportunities. IMO it would make more sense if instead the number of possible matching opportunities was fixed. (4) Also subjective, but a game’s overall score is simply an unweighted average of the square score and sound score. This means that if you got 10/10 square matches but 0/1 sound matches (because only one happened to show up), your score is 50%. I’m not quite sure whether this behavior makes sense or if it should really be weighted based on how many square/sound match opportunities were actually shown.If (1) were fixed I would probably change this review to 5 stars. It’s really irritating to constantly have your “average” score dragged down (or up) by a particularly bad (or good) final round.

First of all, N-Back wasn’t created by this app and its developers, it was made by some scientists who were trying to measure short-term memory an attention. Second, this team proved that the N-Back test can improve short-term memory and focus through repeated tests. Third and finally, while this app is free, it only goes up to the second level, limiting how far you can improve.