It would be great if you could calculate round ups from a credit card as many people use a credit card as their primary transaction account (e.g. to accumulate reward points etc.).
I understand that it might not be possible to take investment funds from the Credit Card so, if that's not possible, I've seen other apps get around that limitation as follows:
  • Credit card transactions monitored and round ups calculated off these
  • Transaction account nominated as funding account
  • Once stated round up threshold reached (e.g. $1000) then funds deducted from funding (transaction) account