My Crytpo Wallet enables you to easily check the balances of Bitcoin and Ethereum addresses, as well as current exchange rates of both cryptocurrencies. Any number of public addresses can be tracked, including offline and hardware wallet 'watch' addresses.
In addition to letting you know balances in Bitcoin or Eth, you are also given the USD (or other selected currency) equivalent, based on current exchange rates.
You have the option of adding a 4 digit PIN that must be spoken before your balances are given.
If you decide to track balances of public Bitcoin / Ethereum addresses, you'll want to have your public addresses handy at setup time, so you can paste them in easily.
The balance information for public addresses is acquired from public blockchains.