The app domain

To show the mini app way of programming applied to a web app, I needed a small but complete enough app idea. High-intensity interval training (HIIT) is a cardiovascular exercise strategy of alternating sets of short periods of intense anaerobic exercise with less intense recovery periods. Many HIIT trainings use HIIT timers, for example, this 30 minute online session from The Body Coach TV YouTube channel.

HIIT training online session with green high intensity timer.
Active period.
HIIT training online session with red low intensity timer.
Resting period.
Compare screenshots from this video, with and without captions.

Video with captions.
Video without captions.

Layout tables must also be hidden from AT users with the ARIA presentation role or aria-hidden state.

My stamp collection
[Stamp Image 1] [Stamp Image 2] [Stamp Image 3]
<table role="presentation">
    <td>[Stamp Image 1]</td>
    <td>[Stamp Image 2]</td>
    <td>[Stamp Image 3]</td>