A tasbih counter does one job: it keeps the number while you repeat a dhikr. You tap once for each dhikr, the screen adds one, and when you reach the goal you set the app tells you. It is the same thing a string of beads does, without the string.
This one runs in your browser — nothing to install, no account, no sign-up. The count is kept on the device you are using, and the page keeps working after you open it once, even with no internet.
The goal is the number you want to finish in one sitting. Four are ready to tap, and you can type any number you like.
Five dhikr sit along the top of the screen. Tapping one switches the counter to it and starts a fresh round, so you always know which dhikr the number belongs to.
Small things decide whether you keep going: a click you can feel, a button your thumb can hit, a colour that is easy on the eyes at Fajr.
Counting dhikr is one part of the day. The same site carries the morning and evening adhkar, the adhkar after prayer and before sleep from Hisn al-Muslim — each with its Arabic text, a meaning, its source, and a counter of its own.
There are also ready-made wird programs: a short list of dhikr you run from beginning to end, with a counter for each one.
The counter and the adhkar are free to open and use. Everything you type or count stays on your device, and you can erase it from the privacy page.