Your smartphone can be used as a universal remote control for your home devices.
App on your smart phone communicates via Wi-Fi with the base station / hub / IR – InfraRed Transmitter, which then translates the command into IR for the devices.
Many products are available that allow you to use your smartphone as a remote. You can build your own using ‘arduino’.
https://github.com/e-tinkers/esp32_ir_remote
Some Sample products –
Pronto is a small hub that’s able to turn your iPhone into a universal remote, allowing it to control a range of electronics and devices within your home using 360 degree infrared.
Philips Pronto universal touch screen remote control lets users easily manage and tailor their home entertainment systems.
Logitech Harmony Hub Smart Home IR Hub & Remote App
Harmony Hub turns your smartphone or tablet into a universal remote, giving you control over your home entertainment and smart home devices.
You can change channels and volume, program favorites, control lights and other smart devices, and build multi-device experiences called Activities. Plus you can do it all even when you’re away from home.
https://www.logitech.com/en-us
ORVIBO Smart IR Blaster Universal Remote Hub
ORVIBO Smart IR Blaster Universal Remote Hub, Mobile Phone & Voice Control to TV, STB, Projector, Sound, Fan, AC, Infrared Devices, Programmable Timer, Works with Alexa, Google, Siri, 2.4Ghz WiFi
https://www.orvibo.com/en/product/allone.html
Sample Apps to Control TV with iPhone
For LG TV
For Sony TV
For Samsung TV
For Panasonic TV
For Vizio TV