Is there a Graft blockchain explorer where you can just input an address to see the balance of it?
No this is not possible due to the private nature of the GRAFT blockchain. However, you can use a command in the CLI wallet to view the transactions associated with your wallet address. Just use the mnemonic seed words from your mobile/desktop wallet to import into your CLI wallet. Get the CLI wallet here: https://www.dropbox.com/sh/3f08lgk3zn6gm0w/AACP2RT2uDqdeMlPJxbhGNL1a/Wallets?dl=0 or follow the instructions on the official github here to compile it yourself: https://github.com/graft-project/GraftNetwork