App that forwards text messages?

On Android, "SMS Forwarder" (the open-source one) is the app most people end up with: it watches incoming messages and forwards them by rule to email, another phone number, Telegram or a webhook. On iPhone, nothing exists — Apple gives apps no access to the message store, so any iOS listing claiming this is fake.

What a forwarding app can do:

• Filter by sender or keyword, and forward only matching messages.
• Send to email, SMS, Telegram, Slack or an HTTP endpoint.
• Run silently in the background (needs SMS permission plus battery exemption).
• Log everything to a local database you can export.

What it cannot do: forward messages from another phone, forward iMessages on iOS, or read WhatsApp/Signal content. It sees only the SMS/MMS that arrive at the device it runs on.

Setup that actually survives: grant SMS permission, disable battery optimisation for the app, and test with a message from a second number. On Xiaomi/Samsung, also allow autostart, or Android will kill it overnight.

Where our app fits. Ultimate Phone Spy runs on Android 4.0+, Windows and macOS (features) and keeps messages in a dashboard with call logs, contacts, social notifications and location, rather than pushing them to a phone. Forwarding and monitoring solve different problems; ours is the record, theirs is the alert.