Please work through the following steps to troubleshoot your double tap function:
If your double tap function is not working correctly (for example: double tapping within TapGenius and the app is not registering the expected character), please try exiting the TapManager and TapGenius apps. Wait 30 seconds and try your input again in a non-TAP application such as notepad or a text messenger.
If the problem persists, please decrease the Double Tap Timeout speed in your TapManager settings and make sure your firmware is up to date.
If none of these steps resolve your issue - please contact support for further assistance.