This is really neat!
Quick question/thought - if the aim is 20yrs of longevity, then what's the future-proofing here for users? For example, what are my export and private backup options? My family has been looking for, and trying apps like this for a while, and we've been burnt by several apps either going out of business, being sold, or "pivoting". Our latest struggle was with Cocoon, which we loved, but has been "bought" - which really means gone dormant until it finally stops working. Having our content stuck time and again has led us to a "no more walled gardens" rule on our photo and memory sharing.