Various digital therapeutics (DTx), which utilize computerized cognitive training (CCT) to improve cognitive functioning, have been tested and released. However, the efficacy of these DTx approaches may be diverse. This study aims to meta-synthesize the associations between mobile applications and cognitive functioning outcomes in older adults with mild cognitive impairment (MCI) or dementia from randomized controlled trials (RCTs). We searched PubMed, EMBASE, Scopus, and Cochrane Library from the inception through the end of June 2024. We selected RCTs using mobile application interventions in older adults with MCI or dementia. Interventions and comparisons included: CCT, intensive CCT (CCT2x), computerized cognitive engagement, progressive resistance training (PRT), CCT plus medication, CCT plus PRT, and medications only. Outcomes of interest included cognitive functioning and other measures of functioning (e.g., activities of daily living [ADLs]). Network meta-analysis was conducted to estimate pooled standardized mean differences (SMDs) with corresponding 95 % confidence intervals (CIs). Of 1,189 studies extracted, 10 RCTs were included in our analysis. CCT2x demonstrated statistically significant improvements in global cognitive function (SMD, 1.21 [95 % CI, 0.69-1.73]), episodic memory (SMD, 0.87 [0.47-1.27]), and working memory (SMD, 0.93 [0.44-1.42]) when compared with controls. For ADLs, CCT significantly reduced functional impairment (SMD, -0.80 [-1.40 to -0.21]). In depressive symptoms, CCT2x was the most effective in reducing symptoms (SMD, -0.77 [-1.08 to -0.45]). Overall, the DTx may be effective in improving cognitive and other functioning outcomes in older adults with MCI or dementia.