Alright, I know everybody must have had the idea to create a wallet for Android/iOS. The issue is that bitcoin's blockchain is approaching 200gb in size.
I reax somewhere (in another forum) that it is possible to abbreviate the mechanism for reading the blockchain. So my idea is simple - create a protocol that makes the blockchain small enough to be able to use on a mobile device. I am sure the wallet client isn't that hard to write.
What are your ideas?
Even with Bitcoin core wallet (on a computer) you can enable pruning and the amount of data saved would become much more bearable. However, you'll still download the whole blockchain.
The wallets today on Android/iOS are SPV wallets, so they rely on servers which hold the blockchain. The idea is not so bad.
I don't know how would you make a "protocol" would make blockchain small. Maybe you can save the data in a different format, but that would not gain much if you keep it all. Or you can keep only the data relevant for your addresses, but that's what pruning does. So what you want to add/improve?