Is it halal to download free apps and have to do tasks to earn money? Or should i stay away from this?
The so-called 'gig' economy is unislamic as it is promoted as giving workers flexibility whilst they are very quiet about how this is being used to undercut workers rights and protections which had to be fought over. It's basically returning people to an early model of capitalism where people were paid by piece rates and workers were journey-men. Read, journee. Workers who work for the day and with no attention to their future.
Of course you are not in a position by yourself to stop the gig economy. And only you yourself know your own circumstances. But I'd suggest that keeping away is halal when you have other options for making a living.