Account Tracker 2.5.1 now available
Added support for refunds (check out the left facing arrow on the transaction screen). These are essentially income transactions but they are treated as negative spending in the budgets and reports.
Added settings for choosing the pair of weeks (for biweekly/fortnightly budgets and reports) and for how to handle reconciling transfers.
As with all updates, I would recommend taking a backup and exporting it off your device before updating.