What's the difference between PayNow, PayLah, Pay Anyone?

No, they are different. Although they serve roughly the same purpose of making Singapore a more cashless society.

PayLah is offered by DBS as a mobile wallet and digital payment method for DBS and POSB users.

PayAnyone is offered by OCBC as a digital cash management tool for OCBC customers i.e. transfers between people using mobile numbers, cash withdrawal from ATMs etc.

PayNow is the government and banking industry initiative to facilitate money transfer and payments between users of different banks in Singapore etc. Once you registered for PayNow and link a designated bank account/mobile number, any payment/transfer can be performed using your mobile number and the money is credited into the designated account.

And most apps including PayLah and PayAnyone should support the PayNow functionality. So use whichever app that meets your needs or spending habits.