There is a slight delay for this method, but you can see if you transaction went thru by pasting your account number into the search bar of secretnodes.com. Also on secretnodes.com, you can look directly at the account of the contract that you called for the transaction.
For example, if you are on the secretswap app “swap” tab, this is the contract that is called:
Look for your account number in the transaction history.
It may not be necessary to call the network each time for minimum fees.
My current understanding of how to manually determine the minimum fee is to look at this contracts “transaction history”. Click “details” on a transaction and then look at the “Gas used”. In the case of this particular contract, the “gas used” tends to be around 930,000. This seems to be the absolute minimum for the contract not to fail and eat your fee. You can use that as a baseline, and most of the txs seem to be going thru with a “gas wanted” of 1,500,000.
It seems like a web interface that reports these “gas wanted” and “gas used” fee averages calculated from the transaction history would be enough.
I’m piecing this together, someone with more knowledge please correct my errors.