Android wallet update 2:
Hey paspi, amazing news!
I've read your post a couple of times now. And still I don't fully understand the way the wallet works or the possible problem.

Maybe you could explain it using an example? I'm not that techy so please keep it simple. I would really like to help you.
Do you see any possibility of a malfunction or a possible scam when the android wallet you're developing uses only the transactions of the last 40 days?
Is this problem only relevant for the minting process or is it necessary to have the whole blockchain on the android device in order to simply send and receive mintcoins?
Maybe it is possible to verify only some blocks of the blockchain instead of having the whole blockchain on the android device. I mean additionally to the blocks from the last 40 days maybe only verify the 100th or the 10000th block of the blockchain. That way it is secured that the correct blockchain is used? Or is it another problem?
Also maybe it is possible to mint using the android device without securing the network? (<-sound stupid but i mean it). As long as enough wallets are run on the laptops and pcs the network is secure.
Thank you for your efforts and your explanations!