WhatsApp — Primary messaging app for individuals and businesses. Use this to talk to any person and business, make restaurant reservations, doctor appointments, etc.
Business discovery & reviews: Google Maps.
Ride hailing apps: Grab, AirAsia, Maxim, InDrive (illegal but can be handy)
Shopping: Shopee, Lazada — Remember to use LazMall and Shopee Mall filter. Your parcels will usually be deposited at the guard counters at your condo.