I've practiced this for as long as I can recall - not because I was told to, but because I found recalling something and working with it in an appropriate mental context worked to cement seemingly limitless amounts of information in my mind.<p>I'm not convinced that an app or any external crutch is required - one simply needs to get in the habit of reflecting on new information, and sporadically testing retention. The first step for me to start the loop is to subvocalise (or vocalise if I'm in private) the pertinent info several times after receipt, which beds the memory of learning something in, and the context, if not the fullness of the information itself. It's enough - it's a hook to trigger recall of the full information - sits in episodic memory as "a thing I said or did", rather than passive "this happened/I heard this" information, and therefore surfaces the entry point easily. If an entertaining association rises at that point, I store that too, as it acts as a mnemonic.<p>I do find myself sometimes doing this with useless information, however, and end up memorising pretty much every bit of information I only intended to retain for 30 seconds (e.g. a chunk of foreign text, ticket numbers, seating plans) - and find myself doing habitual recall on them until they cement like everything else.<p>One thing that the article doesn't touch on but I think is important is sleep - I find if I recall immediately before nodding off the information sticks far more firmly, and I resultantly wake up in the middle of the night with fresh insights. Conversely, when I don't get enough sleep for a prolonged period, my recall definitely gets substantially worse - I find I both can't remember things and if I do, they're distorted, or I don't trust the information.