Platform
Pick your device to see every provider with an official app for it, ranked by security. A browser extension is listed separately: it covers the browser’s traffic only, not the whole device.
Providers shipping a client for a platform, one page per platform. This is the most commercial of the eight taxonomies and the least interesting to the security model: it says what you can install, not what the operator keeps.
A browser extension is not a system client and is counted separately — the difference decides whether traffic outside the browser is covered at all.
U01_platforms has a closed vocabulary of exactly these ten terms: a platform outside the list is not published at all, so this row is the whole of what a record can claim to ship a client for.
What that buys a reader is a word that means the same thing on every record — the platform a record names is one of these, spelled this way, or it is not there.
Browse
Each one opens a list of providers ranked by security. The number shows how many providers it holds today.