As with Windows or any other commercial operating system, in Android there free alternatives to those of payment and these are as good or better than the popular ones, which sometimes exceed them. It is not that Android applications are expensive, but for that reason you are not obliged to pay for an app that you can easily replace with a free one and that in the end does the same, such as a PDF viewer for example.
anti-roid it is precisely the website that collects free alternatives to paid android applications, by way of comparative catalog It shows us the paid applications and to its right the free alternatives and if you click on them, you will find many more.
The page is organized by categories, Games y Applications, each with several very complete subcategories. Of course anti-roid It has its own internal search engine, where you write the name of the payment application and you also come across its respective free alternative.
Furthermore, anti-roid has a voting system to evaluate the free applications, in order to check the quality of the Free Android apps for your Smartphone or tablet.
Link: Antiroid