legalities

You didn't mention which platform(s) or even how you plan to distribute your apps.

For Mac apps, you can distribute them either via the app store or from your own website.

For iOS/TvOS/WatchOS you can only distribute them in-house to staff/employees if you're an enterprise developer member or

via the app store as an individual or company developer. You cannot distribute these apps via your own website.

Contracts? With whom? If you mean you intend to develop apps for hire, then you need to consult an attorney and have them

draw up the proper contract types for the work/relationship you'll be working with. If you mean to distribute apps on either the

Mac or iOS/TvOS stores, you need to be a paid member of the Apple Developer program and sign the contracts Apple provides

for that purpose.

Taxes again will depend on what you plan on doing and where your apps will be sold. Apple manages a lot of the sales/vat etc sorts

of stuff but, in some cases you have to also pay country specific taxes/fees depending on where you are in the world and where the

apps are sold. In general, income from your apps will end up on your personal or company taxes as taxable income which is your

responsibility to manage and pay. As for collecting tax payments, that depends on how you distribute your apps. The App Stores

handle most of that for you but, if you sell apps outside of the store, you're responsible for those taxes.

You do not need to start a business, obtain a business license or a DBA to create and sell apps. You may need to if your country

or county requires it but in general you do not. The type of business will depend on the level of protection you are seeking and wether

you're actually a business to begin with. If your intent is to sell apps as a company rather than under your own name then yes, you

do need to be a business with a business license, tax and banking in place. Having said that, this is only the case when selling apps

on the app stores or your country/county requires it.

You should seek the advice of a competent business attorney and a tax attorney fluent in the laws governing such situations where

you operate.

I appreciate your comment very much. You cared enough to take the time to give me a thorough explanation.