couchbase-lite-ios

You must be aware that notmuch is only the search backend, and for a full MUA you need frontends. I believe the official one is the Emacs one, so it should be fairly usable. There's also a web one [0] you should be able to play with. Another contender in the space (label- and search-centric) is mu and its ui, mu4e [1]. Something else to have in mind. Now if you want something that works on desktop and mobile, something worth a look would be using SQLite and its built-in full-text search... see how far you can go with that. SQLite is available pretty much everywhere, Android even allows full-text search. Now what you have to do is synchronize SQLite dbs. It "shouldn't" be too hard to remove old emails from the db so you can keep X MB worth of it. You can even shoehorn it into couchbase-lite [3][4] so that sync is automagically taken care o

No it's hard and could lead to sad stories. Say your phone holds a few wallets and a hacker breaks in a starts double spending. That would ruin those wallets and I guess there are simpler cases like you just lost your wallet / forgot your password that might be as troubling. So key handling is totally one of those things I'd love to outsource. Actually please let me outsource as much of of the crypto as possible, I don't want to be inventing things. To that end http://www.w3.org/TR/WebCryptoAPI/ looks like a reasonable start. I've also been reading http://datatracker.ietf.org/doc/draft-ietf-jose-cookbook/ and generally trying to get a sense of the least opinionated path I can take. Luckily our iOS lead at Couchbase is experienced writing apps that use cryptographic signing, so he's written up the beginnings of a spec that we'll likely evo