Language category: 1.
Speak Thai (iOS/Android) 2.
Translation (IOS/Android)
Hotel category: 1. Booking
(iOS/Android) 2.
Agoda (iOS/Android) < Android) 2.
daily cost (IOS/Android)
transportation category: 1.
Grab (taxi software in Thailand) 2.
BKK Bangkok mrt (IOS/Android)3.
Google map (IOs/Android) (Apple can bring its own map)
E-travel
food category: public comment (which can also be used in Thailand), tripadviser (which is also very comprehensive in food evaluation), Eatigo (which may have a discount)
entertainment category: Youtube
communication category: Line, Facebook (which these two Thais prefer) and WeChat can also be used
. I hope my answer will be helpful to you and adopted.