Presses Home keys, then types predictable. Useful for disabled people waking up a iPad. This is in circuitPython.

code.py

"""
Whatever state the iPad is in this code will wake the device up
Attach a button to Feather nRF52840. Set the pin on line 21.
WARNING 1: DO NOT HAVE A PASSCODE FOR IPAD!
WARNING 2: NOT FULLY TESTED. Dare say there are some use cases where this will go wrong. Like if iPad doesnt wake up quick enough
WARNING 3: Feel free to adapt line 59 to the app of your choosing BUT if the app isnt on the device it wont work. 
"""
import time
import board
from digitalio import DigitalInOut, Direction, Pull

import adafruit_ble
from adafruit_ble.advertising import Advertisement
from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
from adafruit_ble.services.standard.hid import HIDService
from adafruit_ble.services.standard.device_info import DeviceInfoService
from adafruit_hid.keyboard import Keyboard
from adafruit_hid.keyboard_layout_us import KeyboardLayoutUS
from adafruit_hid.keycode import Keycode

button_1 = DigitalInOut(board.D5)
button_1.direction = Direction.INPUT

hid = HIDService()

device_info = DeviceInfoService(
    software_revision=adafruit_ble.__version__, manufacturer="Ace Centre"
)
advertisement = ProvideServicesAdvertisement(hid)
advertisement.appearance = 961
scan_response = Advertisement()
scan_response.complete_name = "AceWakeButton"

ble = adafruit_ble.BLERadio()
if not ble.connected:
    print("advertising")
    ble.start_advertising(advertisement, scan_response)
else:
    print("already connected")
    print(ble.connections)

k = Keyboard(hid.devices)
kl = KeyboardLayoutUS(k)
while True:
    while not ble.connected:
        pass
    print("Start typing:")

    while ble.connected:
        if button_1.value is False:
            k.press(Keycode.COMMAND, Keycode.H)
            k.release_all()
            k.press(Keycode.COMMAND, Keycode.SPACE)
            k.release_all()
            k.press(Keycode.COMMAND, Keycode.A)
            k.release_all()
            k.send(Keycode.DELETE)
            time.sleep(0.2)
            kl.write("Predictable")
            time.sleep(0.1)
            k.send(Keycode.ENTER)
            time.sleep(0.4)
    ble.start_advertising(advertisement)