To ascertain whether a loan app is registered, you should first scrutinize the app or its official website for any details regarding its registration and licensing. Subsequently, consult the financial regulatory authority in your country, as many have online databases that list registered and licensed lenders. Additionally, it's prudent to read user reviews and check the app's ratings on trusted app stores or financial review sites. Lastly, corroborate the company details specified in the app with official records to ensure authenticity.