Battery Days — your watch battery in days, not in a percentage. • Days of charge left, read straight from the watch • Charge ring around the edge, red below 15% • The percentage is still there, in small print, if you prefer it • Opens and closes in a second. No settings to configure • No account, no cloud, no analytics, no ads, no permissions. Free ───────────── WHY DAYS AND NOT PERCENT "40%" does not answer the question you actually have, which is whether you make it to Sunday without a charger. Days do. The watch already computes that number and keeps it buried — this puts it on one screen, one button away. Below 15% the ring turns red. That is the only threshold that changes what you do, so it is the only one the app treats differently. WHAT IT DOES NOT DO It does not track anything, does not store anything and does not talk to your phone or to any server. It asks for no permissions at all — you can check that in the permission list Garmin Connect shows you before installing. There is nothing to set up: install it, open it, close it. On watches that do not report a days estimate, it shows the percentage instead and says so plainly rather than inventing a number. MADE BY ONE PERSON Battery Days is free, has no ads and no subscriptions, and will stay that way.