Ali Express has a concept of coins in their mobile app. If we check in everyday continuously you can collect some coins based on your regularity. These coins can be used along with money to buy products. But everyday at 12:30pm IST they host a sale where they have products priced at $0.01 and few coins. If you are lucky enough to grab a product on the very second, you get a product for $0.01 and few coins. As coins are earned for free, you literally get your product for free.
But you need to check in everyday and you will start from 1 coin. Few selected products come on this sale . The products usually take hundreds of coins to thousands, so you have to be patient to collect the required number of coins. Also, there will be just 1 or 2 items of each product on sale and are usually gone on the very first second.
This takes the effort but gets you ‘some’ product for free if you are patient and lucky.

