I don't want to enter the thread, but WalletChecker is missing https - therefore I would not use it. Should by easy to fix by them.
Excellent project for learning.
On a side note; I have been using this web based tool to keep track of my paper wallets across multiple forks. No private keys and looks perfect on my phone. It also links out to the chain's corresponding explorer for further balance verification.
WalletChecker.com