Question about the IWD before I buy

This would be the first program I ever payed for and my question is. would it just be a one time payment? or do I have to pay for updates? Also now that I think if it. what will happen when I get a new phone? will it just move to it? or do I have to pay? (sorry for sounding stupid this is new to me.)

its a one time payment (i,e you get free upgrades)
re new phone, I would guess google play would allow you to install OK on that (if same account)

Thank you for the info. and thank you for the reply