Why not just create watch address book in Electrum wallet and import all your wallet addresses?
Much better than trusting any website or explorer.
Because you will be trusting electrum servers. You are just trusting someone else.
When you create an SPV wallet, even in electrum, you are making server requests of all those addresses. Those addresses are obviously of the same person (even though electrum does not save your IPs).
Additionally, using my tool you can check your balabnce in the phone, while traveling, etc. No need to use the same desktop as in the electrum watch only.