Unless the person is the game's developer or a salesman directly associated with the developer or company selling the game, I'd say buy from a store, either brick & mortar or an App Store.
Doesn't matter to me. Some are individual developers and some with a company name. What you should know is many of those with a fancy company name may be one person. I have great games by a person and by a company. If I like it, I play it.