I use Braintree for appdesignvault in thr UK and have found their service to be top notch.
The only issue was Ayden settling the funds into our UK business account every 4 days and getting charged £6 for the privilege. A quick support email fixed that
Yes, Flat UI has its place and not the only way forward. One thing everyone is missing is the author's statement about all knowing Jonny Ive being and an expert in industrial design. UI design is a whole new beast.... That means having a UI with only 10 shades of grey will be the best look