Watcher has something its rivals lack: a demo that shows what you'll get before you connect anything. That's fairer than asking for account access right away. The feature itself is still questionable, since your contact has no clue their edits and deletions are being kept.
Here's what it does. When someone in a chat erases a message, you keep it. When they edit one, Watcher puts the two versions side by side. Timed photos and videos don't disappear either.
There are more commands than similar services offer: connect, a profile with your status, the demo, Premium, inviting a friend and a separate scheme for people who want to promote the bot. We'd start with the demo, because it shows what you get before you hand over access.
Connecting means an outside service gains access to your private chats, and the bot runs nonstop, even while you're offline. The profile doesn't give the Premium price or how it compares with the free mode; those numbers appear only inside the bot.
And the part people tend to skip. Messages get deleted or edited so the sender can take something back, and disappearing media is sent so it won't be kept. Your contact never agreed to a copy. Telegram may consider bots like this a rules violation, and your account is what gets hit.
Toque em uma estrela; dá para mudar o voto depois.