It's very important to make sure the text on your business card is oriented properly before scanning. Remember that programmatically, card scanning still takes place in 2-dimensions, so if text is distorted by taking a picture at an angle, or if the card is rotated, scanning will produce less than desirable results.
By default, the app automatically rotates the card before scanning when incorrect orientation is detected. However, this feature is not perfect, and you may need to tap the rotate button until the card is upright before scanning. If this feature becomes a nuisance, you can turn it off in the settings menu. You can always reopen your images, rotate and re-scan them.
Try making sure to take pictures of your cards straight-on, holding your camera parallel to the card, instead of at an angle, to prevent distorting the text too much for scanning. If the card is photographed at an exaggerated angle, the text may appear too distorted for the OCR to discern text accurately and may display similarly distorted results.
Occasionally the app will send an error message that we could not detect orientation. This is quite alright and usually the card will be shown upright anyways. This typically happens when the image in question is too small, blurry, or the text on the card is very jumbled.