JSEM TU! helps individual cold-water swimmers, groups and clubs organise shared dips, confirm attendance and track consistency. The app is developed by Otakar Zemek of Otužilci Frýdek-Místek.
JSEM TU! is made by cold-water swimmers, for cold-water swimmers. Its detailed personal diary covers cold showers, baths or tubs, and outdoor swimming. Record water and air temperatures, time in the water, location, how you felt before and afterwards, and a personal note. Compare each new entry with your previous session of the same type.
The diary turns your entries into interactive charts on the Statistics tab, with basic and detailed statistics for a week, month, year or custom period. Create a vertical 9:16 Stories image for social media using selected statistics, a chart or up to three of your own photos. Move, zoom and crop the photo, then share the result directly or save it as a PNG.
Export all your diary entries, or filter by period, activity types and fields, to Excel XLS, CSV, TSV or JSON.
Child accounts and internet access
When registering, children aged 9–15 must also provide a parent’s name and separate email address. The parent receives a link to approve or decline the request. The account remains unavailable until approval is given; signing in with Google does not bypass this requirement.
Sign in with email and password or with Google. The entire app, including the cold-water swimming diary, requires an internet connection. Local caching does not provide an offline mode. How parental approval works.
The app’s own website has further information at jsemtu.info/otuzko. That website and the app interface are currently in Czech.