Adding Emulators to the RP2

Here is a list of extra emulators that can be installed on the RP2, either as cores within RetroArch, or as apps for Android, and how they perform. The key to the "Performance" column is:


 * A: Plays almost all of the system's games at full speed (or better, for example increased resolution) with few to no glitches.
 * B: Plays many of the system's games at full speed, with minor glitches.
 * C: Technically plays some of the system's games, but rarely or never at full speed, or with major glitches.
 * D: Does not run any of the system's games in a playable state.

Emulator Apps in Android
The key to the "Cost" column is:


 * Free: Completely free.
 * Donation: Completely free, but a voluntary donation is requested.
 * Trial: A free version is available, but limited in some way, to encourage users to buy the full/pro version.
 * Paid: No free or trial version; only available as a paid app.