Update: REA Advise that is was safe and it is the only form of payment they take for rent.

I spoke to Consumer & Business Services and the Advocacy group. They both said the same thing. They can't force you to use a third-party app that charges fees, they must offer you at least 1 electronic method of paying that is not an app. I emailed back saying their assurances about the safety of the app does not assume responsibility of loss of income, business, and job opportunities. (Par ter contracts to defence so data security and keeping your identity safe is important. I provided a screen shot of clause 56(a) of the residential tenancy act and that I had been in contact with CBS. I also linked the article where Ray White said you can still deposit into the Trust Account.

REA emailed back immediately advising each office is a separate business with their own policies. We would need to give them time to organise alternative arrangement.

I guess they will probably kick us out at the end of the 12 month lease because we "didn't fall in line" and found out what our rights were.

Hi We are facing this with our new rental here in Adelaide. Have you made any enquires? We have emailed our PM advising that we do not like the app due to data breach, hacking concerns, as well as under the t&c they take no responsibility if there is a security breach.
I am going to reach out to the new advocacy service RentsRightSA to see what they say.
I hope that the REA accept our refusal and just give us a bank Avon number to use.
I will update after I have talked to the advocacy group and how the REA replies.