USK – http://www.usk.de/en/
Unterhaltungssoftware Selbstkontrolle (USK) is the German abbreviation for the Entertainment Software Self-Regulation Body, an organisation which has been voluntarily established by the computer games industry. It is responsible for the classification of computer games in Germany.
ESRB – http://www.esrb.org/
The Entertainment Software Rating Board (ESRB) is the non-profit, self-regulatory body that assigns ratings for video games and apps so parents can make informed choices. The ESRB rating system encompasses guidance about age-appropriateness, content, and interactive elements. As part of its self-regulatory role for the video game industry the ESRB also enforces industry-adopted advertising guidelines and helps ensure responsible web and mobile privacy practices under its Privacy Online program. ESRB was established in 1994 by the Entertainment Software Association (ESA).
COPPA – http://www.coppa.org/
Websites that are collecting information from children under the age of thirteen are required to comply with Federal Trade Commission ( FTC ) Children’s Online Privacy Protection Act (COPPA).
Pan European Game Information (PEGI) is a European video game content rating system established to help European parents make informed decisions on buying computer games with logos on games boxes. It was developed by the Interactive Software Federation of Europe (ISFE) and came into use in April 2003; it replaced many national age rating systems with a single European system.
CTIA Mobile Application Rating System –
The CTIA – The Wireless Association, an industry trade group, collaborated with the ESRB to largely apply ESRB’s rating system to mobile devices. It was launched in 2011, with Apple and Google being notable abstentions from subscribing companies.
Google App Store Ratings
Apple App Store ratings