The summary.
UPGRADE TESTING IS THE MOST NEGLECTED AND MOST DAMAGING GAP
It affects existing users, who have data, and a failure on launch leaves them with no route to a fix.
Keep a written pre-release checklist covering rotation, backgrounding, permissions, no network, low storage, largest font size, and upgrade.
A MODEST PHYSICAL DEVICE REVEALS WHAT EVERYTHING ELSE CONCEALS
And test contrast outdoors — screens are used in sunlight here routinely.
MONITOR VERSION ADOPTION
It tells you how long an old version persists, which determines how long you must support it.
Segment everything by platform, version, device and country — aggregate figures conceal problems affecting one segment.
KEEP THE MAPPING FILE FOR EVERY RELEASE
Without it an obfuscated crash trace is unreadable. And add breadcrumbs — a stack trace without context frequently does not explain the cause.
PRIORITISE LAUNCH CRASHES ABOVE EVERYTHING
The user cannot reach a fix.
MOST USERS WHO INSTALL NEVER RETURN AFTER THE FIRST SESSION
Shorten the path to value, delay account creation and permissions, and design the empty state deliberately — it is the first thing every new user sees.
RETENTION MATTERS MORE THAN INSTALLS
Installs that do not return cost money and deliver nothing.
