That's less than 1% over one week. The APR would closer to 15-20% (depending on salary, pay frequency, etc.).
For 1 week: 3 / 360 = 0.8%
For 52 weeks: (3 * 52) / (360 / 52) = 0.8%
Or is it that Even is holding on to effectively a weeks worth of pay at all times, and we're calculating interest based on $360 of principal? Or is compounding coming into play somewhere?