warning

(1) CAUTION WITH EPILEPSY

Do not use the app irresponsibly when you are around people with epilepsy or if you have epilepsy yourself. Why? Taxi Hold'em can be turned on to a pretty fast pace. The black and yellow flashing image can cause someone with epilepsy to be triggered.

This is what wikipedia says on the subject:

Photosensitive epilepsy is a form of epilepsy in which seizures are triggered by visual stimuli that form patterns in time or space, such as flashing lights, bold, regular patterns, or regular moving patterns.

Some more details can be read on: cellphonesafety

People with photosensitive epilepsy can have seizures triggered by flickering or flashing in the 4 to 59 flashes per second (Hertz) range with a peak sensitivity at 20 flashes per second as well as quick changes from dark to light (like strobe lights). When content violates either the general flash threshold or the red flash threshold, users are warned in a way that they can avoid it.

crash

(2) FOR THE OVERLY FAITHFULL:

When you use Taxi Hold'em to get hold of a cab, please do not put all your faith into the power of the app and stand in front of a cab! The cab driver might be distracted, miss the app signalling, and run you over.. ;)