Spare5 is described as 'Got spare time? Get paid when you spend some of it with us.Great companies want your help improving their products. You get paid to complete quick tasks on your iPhone like rating and classifying photos, taking surveys, suggesting better text, and calling businesses to verify' and is an app in the online services category. There are more than 10 alternatives to Spare5 for a variety of platforms, including Web-based, Windows, iPhone, iPad and Mozilla Firefox apps. The best Spare5 alternative is Amazon Mechanical Turk. It's not free, so if you're looking for a free alternative, you could try dscout or ParticipAid. Other great apps like Spare5 are SerpClix, Scale, Prolific Academic and Fancy Hands.
Like Spare5, mTurk provides microtasks to make money.