you can set extremely low transaction fee if need it. For example, I payed $0.31 for sending $70 in Bitcoin equivalent. It took approximately 40 minutes to get two confirmations.
OWNR wallet use Bitcoin legacy address type as "Default" address and they have three fee types :
The possibility that you have bought at the cheapest possible fees is weak.
I think you have paid the lowest fees among the options above.
There is no option to amend fees, so you will not be able to send with the lowest possible fees.
OWNR wallet also focuses on developing currency exchange interfaces, including more altcoins at the expense of technical development and the possibility of changing fees.
The wallet is designed for the novice user who buys Bitcoin to make profits, so it is impossible to be the cheapest fees "wallet"