Just want to say I love your apps making cold wallet spending super easy. =)
This wallet has a centralized API that goes against what bitcoin stands for. If a million people were doing some serious business with the wallet and someone wanted tos crew them over they coudl attack the server(s) and poof your wallet doesn't work.
Hence your wallet's fate is always in the hands of a centralized person(s)... and you will always get this what happened in this post:
https://bitcointalksearch.org/topic/m.4473315I tried to contact these people so I can make another "super node" using Devcoin but to no avail. I liked the interface and ported it over to Devcoin only to learn that all communications are happening via a central API that this company has control over (so its not really open source after all), alas I moved onto using bitcoinj which is totally decentralized and doesn't have a big problem with downloading block data since it is using checkpoints and only downloading last 5 weeks of data.
You would simply backup your wallet and if you re-install a new version of the wallet you can import your keys again later. The whole "not having to download the blockchain" is actually a bad thing not a good one.
So your claim of open source does not stand, unless you open up the source to your API which I can then use to port my application.
The claim here:
https://bitcointalksearch.org/topic/m.3160266 as to why SPV store's are not good because you can't import arbritraty private keys without redownloading the entire blockchain from the genesis block node is a mute point and doesn't defeat the notion of SPV store being better than this proprietary private API. When someone wants to use the android wallet they simply transfer coins over to it without importing your QT wallet private key. Infact it is dangerous to even dump your private key so to encourage this behaviour is bad anyways.
The bitcoinj wallet will allow you to create a new key where you would send coins from your other wallet(s) to it and then you go from there. The SPV store will remember all transactions related to its own wallet from the time you installed the application. If you reinstall the application it will redownload from the last checkpoint which is the earliest time that you could have sent any coins for the wallet to care anyways.
Even if we update the checkpoints so the user would only ever have to download 5 weeks of data, by importing an older key from an older bitcoinj install, I believe since the hash of the blocks are saved relating to the transactions which the wallet would care about it would reimport these blocks when you import your old wallet.
About cold storage, someone could double spend you with a higher mining fee so its not really safe, NFC/Bluetooth available in bitcoinj is essentially the same thing.
