Since initially publishing several apps on Google Play, Google's terms and conditions have changed, meaning I am now obliged to provide a privacy policy for my apps due to their use of certain device permissions.
In a nutshell, my apps do not collect or transmit personal data for use by either myself or third parties.
Apps such as Skaterbase which, by design, collate user data do not transmit or externally use this data at all, it remains purely on the device upon which it was entered unless the user chooses to transfer or make a backup of the database by any of the means available (such as Google Drive). Skaterbase itself is not subject to Googles revised T&C's because it doesn't currently use any special permissions such at contact access or the camera. Skaterbase also employs a commonly used system called Flurry to collect anonymous stats about which parts of the app get used the most.
Bomb Bunny Boogle uses a custom leaderboard feature to track player scores. To implement this it uses a combination of the unique ID of the device it is installed on coupled with the leaderboard name entered by the user. This is purely used so that the users scores can be matched to a device and retrieved from the leaderboard for display. No other personal data is used at all.