I’m one of the iOS devs on the team, thought I’d chime in as this issue has gained some mystery and sense of voodoo! It’s all explainable though, so hopefully I can shed some light.
First off, I’m really sorry you weren’t able to transfer these amounts into your goal!
We’ve fixed the issue, and it wasn’t caused by the use of imprecise types.
Developers amongst you may rightly spot that use of floating point types can lead to rounding errors, and is fundamentally a flawed way to represent currency transactions.
We represent amounts using a native type called NSDecimalNumber. This type is specialised for dealing with base-10 arithmetic, and in particular, is perfect for storing and calculating currencies and amounts, without error.
In this scenario, the Apple API we were using encountered issues when trying to convert locale-specific strings to NSDecimalNumbers, ie how we take your typed text input, accounted for the region you may be in (eg commas instead of decimals in most of Europe), and turn it into it’s currency representation to be transferred to the goal.
It didn’t seem to matter which locale your device was using though, it caused issues with certain amounts. There are countless numbers which would have failed to send, and certainly nothing magic about these numbers, although in the spirit of the holidays, you could go on an Easter egg search for them.
Trivia: the smallest amount I could spot was 0.07
Apologies once again and hope the update makes it’s way to you soon!