National Australia Bank's online only subsidiary UBank brand achieved "a double-digit percentage increase in revenue" over the year to March 2016, the bank disclosed yesterday.NAB's half-yearly disclosure documents earlier this month omitted any material mention of the state of play for its now eight year old UBank brand. The bank refreshed the look of UBank brand in early 2016.The deposit book of UBank had decreased over each half of NAB's 2015 financial year. NAB last reported the deposit book to be A$15.7 billion.Following a media briefing in Melbourne NAB shared a single financial indicator, on revenue growth, reported above. Double-digit revenue growth at UBank only matches the rate already reported by NAB for its personal banking division in Australia.Gavin Slater, group executive for personal banking was able to shed no light on when NAB may catch up with ANZ and introduce Apple Pay, to complement the wallet for Android smart phones NAB has now.Asked how long before Apple might wait before allowing another bank into Apple Pay, Slater responded "don't know".Also asked how long might be the exclusivity period ANZ might have with Apple over Apple Pay, Slater again said "don't know".