Cognitive deficits are often present in major depressive disorder (MDD) and negatively impact functional outcomes. However, it remains challenging to assess these impairments in clinical and research settings. Smartphone applications provide the opportunity to measure cognitive impairments in an accessible way. In this study, 24 individuals with MDD and 34 healthy controls (HC) completed the Trail Making Tests (TMT), and the smartphone-based versions, named the Jewels Trail Tests (JTT). Significant positive relationships between the JTT and TMT were observed with a moderate concurrent validity for Parts A and strong concurrent validity for Parts B. The intraclass correlations showed moderate test-retest reliability for Part A of the JTT and good reliability for Part B. This study did not find significant differences between the MDD and HC groups completion time. Lastly, higher sleep quality was associated with a faster completion time on the speed processing task over a period of three months.