Assessment of Peyronie's disease with penile injection is invasive and uncomfortable. We developed a smartphone application (UWPEN) to assess penile angulation in the home environment. The purpose of this study was to compare clinician and patient measurements and assess the patient experience with UWPEN in a clinical setting. We prospectively enrolled patients with Peyronie's disease undergoing intracavernosal injection of alprostadil. Penile angulation and narrowing were then assessed by patients and clinicians using UWPEN and compared to values obtained via a goniometer and a ruler (gold standard). Measurements were compared using the Pearson correlation test. Upon completion of measurements, patients were surveyed regarding the ease of use, confidence with use, and measurement preferences. Twenty patients were enrolled in the study; two patients were excluded for poor penile turgidity after a maximum dosage of intracavernosal alprostadil. Correlation between UWPEN and gold standard measurements by patients and clinicians was R = 0.55 (p = 0.01) and R = 0.87 (p < 0.01) for dorsal measurements, R = 0.62 (p = 0.01) and R = 0.77 (p < 0.01) for lateral measurements, and R = 0.73 (p < 0.01) and R = 0.64 (p < 0.01) for girth measurements, respectively. Prior evaluation of correlation suggests a strong correlation at R = 0.8, and good correlation at R = 0.5. Overall, patients preferred using UWPEN to traditional measurements, and 75% reported UWPEN as their first preference for measurements. UWPEN enables patients to assess their disease severity with good correlation to gold standard measurements. Patients prefer mobile platforms for disease monitoring, and development of technology for disease monitoring should be a priority within the Peyronie's disease research community.