Yes sorry about this, Jelly bean is no longer supported unfortunately. You can contact us at support with proof of original purchase, we might be able to organise a replacement (the older version of iReal Pro as it was before it was updated it to beyond Jelly bean).
Please allow a little time for us to respond. Thanks.
If you want to run the latest version of iReal Pro, you would need to now run a more up to date Android OS.