This depends on your needs:
Automatic Timer - Most current air conditioners come with automatic timers. You’ll be able to program room temperatures that complement your family’s work, sleeping, and activity schedules. This will keep your home cool and welcoming when people are there and save on electricity when everyone’s out. If you have solar panels, you can also time your air conditioner to run during the day for maximum savings. This use of cheap solar energy will leave you with lower electricity bills and a cool home when you come back in the evening.
Many modern options are also wi-fi connected, which enables you to raise and lower individual room temperatures any time & anywhere via your mobile phone. While not strictly necessary, this convenient control appeals to many.
Room sensors - alert your air conditioner when people are in or out of a room. Your air conditioner will then act accordingly, reserving energy for empty rooms and providing it to occupied rooms. This option isn’t necessary by any means but could be useful if your family tends to move in and out of various rooms without any particular pattern.
Dehumidifier - If you live in a year-round dry area, you probably don’t need one. But if your area experiences high humidity or seasonal rains, a dehumidifier is a must
Demand Response Technology - Air conditioners with Demand Response Mode Technology (DRMT) allow your electricity distributor to switch your aircon to economy mode during periods of high grid demand — for instance, extremely hot days and evenings.