> Hopefully banks the world over will start to standardise their API's and we'll have access to more and more third party apps which can help people with their finances!

I got good news for you, Europe has already been working on a solution for this for a long time, finally coming to fruition now. Nordigen seems to be using PSD2 as well.

More info: https://en.wikipedia.org/wiki/Payment_Services_Directive