I have implemented card.io into an app and the performance when opening the credit card scanning activity (CreditIOActivity) opens quickly on most devices. But on the Nexus 10, running Android 4.4.2, it can take as much as 5 seconds for the scanning activity to load when called from my app. Though this long delay does NOT occur in the sample app card.io provides with their SDK. I am thinking it may be a memory issue causing the slow load time when opening from within my app, but that does not explain why the performance is near identical to the sample app on other devices.
All help is greatly appreciated.
Are you checking CardIOActivity.canReadCardWithCamera(this) in your activity's onResume() or similar? There's some static initialization that card.io needs. If it can be triggered early, it doesn't have to happen when the user is waiting.