Background and Objectives: Bland new smartphone application (JOIN) provides sharing text, neuroimaging, photos and videos and we are securely able to communicate among stroke team. Our aim is to investigate whether JOIN would shorten the duration from admission to thrombolysis and mechanical thrombectomy in hyper-acute ischemic stroke patients. Methods: Between October 2012 to March 2018, acute ischemic stroke patients with thrombolysis and/or mechanical thrombectomy were enrolled. We divided all patients into two groups, 1) pre-JOIIN group as conventional communication system was conducted until September 2015, and 2) JOIN group as we started to use JOIN on smartphone after October 2015. We compared door to image time (DIT), image to needle time (INT), door to needle time (DNT) for thrombolysis, and DIT, image to puncture time (IPT), door to puncture time (DTP) for thrombectomy between pre-JOIN group and JOIN group. Results: We retrospectively enrolled 129 patients (66% male, median age 69 years-old, median NIHSS score 8). JOIN group was 53 patients and pre-JOIN group was 76 patients. In all patients, Thrombolysis was 99 patients (alone 69), thrombectomy was 60 patients (alone 30), and combined thrombolysis and thrombectomy was 30 patients. There was no significant difference of DIT between JOIN group and pre-JOIN group (22 min vs. 24 min, p=0.484). Interestingly, DNT, DPT, INT, and IPT in JOIN group were significantly shorter than that of pre-JOIN group (DNT; 62 min for JOIN group vs. 72 min for pre-JOIN group, p=0.039; INT 41 min vs. 48 min, p=0.005; DPT 106 min vs. 129 min, p=0.046; IPT 89 min vs. 117 min, p=0.004; Figure). Conclusion: JOIN should play an important role in shortening the elapsed time for reperfusion therapy, especially after undergoing initial brain image.