Objectives. To evaluate the usefulness of a novel acoustic uroflowmetry- (UFM-) based mobile application (app) voiding diary (VD) focusing on the (1) compliance and (2) correlation with a conventional paper-based VD. Materials and Methods. A total of 78 patients were included between December 2019 and June 2020, and a subsequent review of all data was performed. The analyzed data were as follows: (1) survey of convenience/satisfaction/preference comparing the two methods, (2) compliance regarding the completeness of both methods, and (3) correlation of each metric (24-hour urine volume, nocturnal urine volume, nocturnal polyuria index, total number of voids, number of daytime voids, number of nocturnal voids, and maximal bladder capacity) between the two methods. Results. The survey results of convenience, satisfaction, and preference were as follows. With regard to convenience and satisfaction area, higher scores are reported in the mobile app VD (
mean
±
standard
deviation
(SD); convenience:
7.47
±
2.19
[app] vs.
4.20
±
2.49
[paper]; satisfaction:
7.36
±
2.17
[app] vs.
5.07
±
2.65
[paper]). The median score of the overall preference for using the mobile app instead of the paper-based VD was 9 out of 10 (
mean
±
SD
7.82
±
2.68
). We also found a good correlation between the two methods for nocturnal urine volume (
r
=
0.55
,
p
=
0.04
), nocturnal polyuria index (
r
=
0.66
,
p
=
0.23
), total number of voids (
r
=
0.9
,
p
=
0.02
), number of nocturnal voids (
r
=
0.83
,
p
=
0.02
), and maximal bladder capacity (
r
=
0.89
,
p
=
0.04
). Conclusion. The acoustic UFM-based mobile app VD demonstrated favorable findings compared to the conventional paper-based VD.