Simple Payment Verification (SPV) clients download only a small subset of the blockchain. This allows low resource devices, such as mobile phones, embedded devices, or tablets, to be able to verify the transactions.
A complete Ethereum blockchain and node are not required in this case, and SPV clients can still validate the execution of transactions. SPV clients are also called light clients. This idea is similar to Bitcoin SPV clients.
There is a wallet available from Jaxx (https://jaxx.io/), which can be installed on iOS and Android, which provides the SPV functionality.
