If you are making something like 200 euro per year by selling an app the requisite of registering for a "ditta individuale" falls off. But my address would be still there published because of this lawIf your sales or activities are regular or continuous, you are considered to be conducting a business activity. In this case, you would need to register a business, such as a “ditta individuale” (sole proprietorship) or another type of business entity.