I want to share exblo, a bare-bones, proof-of-concept block explorer, born of our need to review transactions during testing of our other apps on Testnet.
It currently can find a transaction by its ID, it is running on Zebra 1.8.0 on Testnet. A known issue is that the calculation of the fee is not accurate if there are non-coinbase transparent components.
Hopefully it helps other teams in their validation