See the Wikipedia page for more information please.
They don't. Flashing square matching and letter sound matching are two independent things to keep track of. Flashing square position match only with the flashing square position N steps earlier if they are the same. Same thing with letter matching.
The eye button should be pressed when square positions match and the ear button when letters match.
While it might seem like a good idea to have immediate feedback whether you did right or wrong, it can also be distracting as you are constantly monitoring (and evaluating) your performance. It is better to fully and maximally concentrate on the task itself and get feedback at the end of the round.
Automatically set level gives you less chance to stay on one particular level and to learn good at that level only (i.e. learn memory tricks to be good at that level only).
Use the 'customer support' button in the help section of the game to send e-mail please. We pay attention to only constructive feedback though. So, keep 'em coming but remember to behave :)
If you are reporting a bug, include as much information as possible please (preferably clear step-by-step instructions). Note that if the bug cannot be reproduced by the developer, it is almost impossible to fix.
Unfortunately, we haven't been able reproduce this issue. Please, let us know if you have a reliable way to reproduce this (see FAQ 5 please.)
Here are some steps you can try to fix this. Restart by fully exiting the app, and reopening it. If that doesn't help, please try the following:
Both, visual (eye) and audio (ear), buttons should be pressed. The buttons stay in pressed state (i.e. dimmed) until next position and sound are presented.
Setting 'DAILY FIRST N' sets N level for the first game each day. UNCHANGED means that N is the same as where you left of in the last game, 1 sets N always to one and MY MAX sets N to the highest N you've ever reached.
Tap restore purchases button on the Premium dialog.
Yes, but you need the Premium version. If it doesn't work instantly after Premium upgrade, try restarting the game. Make sure cloud saving is enabled on your device.
It's not exactly missing because it's not actually needed. Eight squares are enough challenging to train your brain.
Trend indicates your general direction of improvement. This is useful if your day-to-day score varies a lot.
In version 2.2.1 (and earlier), the DAY label in statistics graph indicated how many days ago you started playing and in newer versions it counts only those days you have actually played. This reflects your progression based on your effort better.
Any memory trick that steers you away from intuitively keeping letters and square positions in your short term memory is more likely to train you to use that memory trick than improve your fluid intelligence.
When N=3, you have a match if the flashing square's position is the same as the square's position shown three square's earlier (eye button should be pressed). Similarly, you have a match if the letter sound is the same as the letter sound presented three letter sounds earlier (ear button should be pressed). The same logic applies as N increases: N=4 -> remember 4 last square positions and letter sounds, N=5 -> remember 5 and so on.
Press DUAL 1-BACK TUTORIAL or DUAL 2-BACK TUTORIAL button in the HELP section of the app.