I like the idea of this. Not only is the historic data interesting, I suspect just taking time to reflect on your days would likely improve happiness in an of i

I like the idea of this. Not only is the historic data interesting, I suspect just taking time to reflect on your days would likely improve happiness in an of itself (e.g. if you know anyone who is doing one of those 100 happy days challenge). However, the arguments against the web are a bit flimsy IMO. Data on the web is ephemeral only if you put it in an ephemeral store. Put it in localStorage! It's highly unlikely you'd exceed some quota (usually 10mb) with the kind of data you're storing, plus user's are offered chance to expand quota usually. Or if you want something that goes above and beyond that (or what you have with a "native app") you could integrate with Dropbox's datastore API [0] and have data available on any machines I choose to use. [0] https://www.dropbox.com/developers/datastore/docs/js https://www.dropbox.com/developers/datastore/docs/js