Tashlich Prayer is an iPhone app developed by RustyBrick Inc., available for free in the Education & Reference category. The app focuses on the Tashlich Prayer ceremony, traditionally recited during the days of awe between Rosh Hashana and Yom Kippur. It guides users on the proper time to say the prayer and provides the text in Hebrew (short), Hebrew (full), and English forms.

In loving memory of Joseph M. Katzenstein, the app embodies his family tradition of reciting Tashlich as a unit to imbue the mundane with holiness. The app encourages users to continue this tradition with their family and friends, keeping Joe's memory alive through the practice of using the ordinary to promote the sacred.