Thanks.

The difference is convenience. Let's suppose you have 10 addresses with positive balance, from 3 different wallets. One hardware wallet, a mobile and a desktop wallet.

Let's say you receive weekly money from bounties in one wallet, money from services you do in the internet in another wallet and some other wallet from trading in exchanges. You also sell some btc from one wallet or transfer them to someone else.

So your balance is always changing. How to track your overall balance?
You would need to go to block explorer and search each of those 10 addersses one by one and sum those balances. That's is a lot time consuming. It is more convenient just to use my tool.

Just added "sum balance" function.