KLSX Join the TestFlight beta

Get to gaming

KLSX plays the PlayStation, Game Boy, Game Boy Advance, Nintendo 64 and PSP games you own, on iPhone and iPad. Every emulator is built in.

Copy it in, then play

Seconds

First, tap + in KLSX, or drop files into its folder in the Files app.

A moment

Then KLSX sorts them by system, stacks the discs of one game into one tile and finds the cover.

As long as you like

After that it’s all playing. Quitting saves your place; the next tap carries on.

  1. First, tap + in KLSX, or drop files into its folder in the Files app.
  2. Then KLSX sorts them by system, stacks the discs of one game into one tile and finds the cover.
  3. After that it’s all playing. Quitting saves your place; the next tap carries on.

Five systems. Nothing to install.

See which folder KLSX puts it in. The file stays on your device.

PlayStation

Reads
.cue with its .bin tracks, .chd, .pbp, .iso, .img, .ccd, .mdf and .m3u, zipped or notDiscs named “(Disc 1)”, “(Disc 2)” stack into one tile
BIOS
OptionalWithout one, a built-in replacement starts your games. Add the one from your own console and KLSX checks it, labels its region and renames it.
Saves
A memory card per game, shared by its discsStandard 128 KB .mcd cards you can import, export, copy between and assign per slot
Extras
Light guns, analog sticks, 2× resolutionLight-gun games are recognized by disc serial: touch the picture to aim and shoot
Emulator
PCSX-ReARMedGNU GPL v2 or later

Game Boy and Game Boy Color

Reads
.gb, .gbc and .sgb, zipped or not
Boot ROM
Built inSameBoy’s own open-source boot ROMs, so there’s nothing to find
Saves
Battery saves as .srm, plus .rtc for clock cartridgesThe format other emulators use, so saves move in and out
Extras
Color for original Game Boy gamesOr one of four classic screen tints; motion and rumble cartridges work too
Emulator
SameBoyMIT (Expat)

Game Boy Advance

Reads
.gba and .agb, zipped or not
BIOS
Not neededA built-in replacement starts every game
Saves
Battery saves as .srm in the Saves folderWritten within seconds of the game saving, and when you pause or quit
Extras
Sun, tilt, rotation and rumble cartridgesYour phone stands in for the sensor that was in the cartridge
Emulator
mGBAMozilla Public License 2.0

Nintendo 64

Reads
.z64, .n64 and .v64, zipped or not
BIOS
Not needed
Saves
Battery saves as .srmPlug a Memory Pak or a Rumble Pak into the controller in Settings
Picture
OpenGL ES 3, with a resolution setting
Emulator
Mupen64Plus-Next with GLideN64GNU GPL v2 or later, with GPL v3 parts

PSP

Reads
.iso, .cso, .chd, .pbp and .elfKLSX looks inside .iso, .chd and .pbp files to tell PSP games from PlayStation discs
Firmware
Not needed
Saves
An emulated Memory Stick in the PSP’s Saves folder
Picture
OpenGL ES 3, with a resolution setting
Emulator
PPSSPPGNU GPL v2 or later, with GPL v3 parts
Editing the touch layout in KLSX: every control outlined, the A and B buttons selected, with a Size slider and Save Layout Controller Buttons in KLSX: the controller’s A and B swapped for Game Boy games, every other button on its console default KLSX after connecting to a TV called Living Room, asking whether to show the game on both screens or use the phone as the controller

Phone, Duo or TV

On any iPhone or iPad, KLSX plays in portrait or landscape. On iPhone Duo it uses both screens: closed, the outer one; open, the big inner one with the controls beside the picture; half-folded, the game on top and the controls below. Each screen shape keeps its own touch layout. Pick up a controller and the touch controls step aside; plug in a TV and your phone becomes the controller.

Join the TestFlight beta Tune the screen and controls

Tune the screen and controls

Choose how the pixels look.

Sharp pixels keeps every edge. Smooth softens them. CRT scanlines brings back the lines of an old TV.

Let the game show through.

Touch control opacity fades the buttons until they barely cover the picture.

Keep the controls off the picture.

In landscape on a big screen, the picture shrinks a little so the controls sit beside it instead of on top.

See how hard it’s working.

Show frame rate puts frames per second and the emulation load in the corner. A load near 100% means the device is at its limit.

Pick up a controller.

Connect a Bluetooth or USB controller and the touch controls step aside. Remap its buttons per controller and per console.

Then move anything.

Edit Touch Controls Layout lets you drag or pinch any control, or the game screen itself, and keep it for one game or a whole system.

First, real sunlight

Some cartridges had a sensor inside. KLSX spots them the first time the game starts and asks how your phone should stand in.

Cartridge Add-ons

Solar Sensor

  • Sun Dial
  • Real Sunlight
  • Camera
  • Screen Brightness

Uses the UV index where you are from Apple Weather, like the real sensor. Needs your location and an internet connection.

Tilt Sensor

  • Move the Phone
  • Controller Stick

Tilt the phone to roll the game. Set Level makes the way you’re holding it the flat.

Rotation Sensor

  • Move the Phone
  • Controller Stick

The gyroscope turns the game as you turn the phone.

Rumble

  • Phone
  • Controller
  • Both
  • Off

Rumble cartridges shake the phone, the controller in your hands, or both.

  1. Solar Sensor
  2. Tilt Sensor
  3. Rotation Sensor
  4. Rumble

Questions

Does KLSX come with games?

No. No games and no BIOS files are included. KLSX plays games you own: disc images made from your own discs and cartridges you’ve backed up yourself.

Do I need a BIOS?

No. Game Boy, Game Boy Advance, Nintendo 64 and PSP games start without one. PlayStation games use a built-in replacement unless you add the BIOS from your own PlayStation, which some games run better with.

Where do my saves go?

Into Files › On My iPhone › KLSX, a folder per system, so you can back them up or bring saves from another emulator. Every game also has eight save-state slots and a resume point written when you quit or lock the phone.

The KLSX in-game menu for Tobu Tobu Girl Deluxe: Resume, Fast Forward, and eight save-state slots, three of them filled with pictures of the game

Can I play on a TV?

Yes. With AirPlay Screen Mirroring or a USB-C to HDMI adapter, the game plays full screen on the TV and your phone can become the controller. Unplug the TV and the game pauses.

Will it run well on my iPhone?

iOS doesn’t let apps compile code on the fly, so every emulator in KLSX runs without it. Game Boy and Game Boy Advance games are light work; PlayStation, Nintendo 64 and PSP games ask more of a phone, the last two most of all. Show frame rate tells you how close yours is to its limit.

Is KLSX open source?

Yes. KLSX is free software under the GNU General Public License, version 3, built on PCSX-ReARMed, SameBoy, mGBA, Mupen64Plus-Next and PPSSPP.

Right where you left off

KLSX is in beta on TestFlight for iPhone and iPad, iOS 18 or later.

Join the TestFlight beta