Not on the phone. A flip phone texts over SMS and MMS, and iMessage runs only on Apple devices. With Decaf, iMessage stays on at home, on your Mac, and the texts that matter reach the flip phone as SMS, with a way to reply.
Whichever flip phone it is, a TCL Flip or a Nokia 2780, say, texts and group texts go over SMS and MMS. A group chat with iPhone friends arrives as a plain group text, without reactions or typing dots. The KaiOS phones can’t run Android apps, so the Android iMessage workarounds don’t apply, and Sunbeam says its phones don’t support iMessage, WhatsApp, Signal or RCS (Sunbeam support).
Sunbeam, which makes flip phones for this switch, describes what happens when a number leaves an iPhone: texts from iPhone friends go missing until the number is deregistered, and group chats split. Some owners waited 30 days for group texts to come back (Sunbeam, February 2026). Once you deregister (Apple’s page for that), iPhones that text you fall back to SMS, and the group chats you were in go on without you.
Decaf is a calm iMessage Mac app that relays time-sensitive and important texts to a second phone. Your iPhone keeps your main number and stays home, plugged in. The flip phone gets a number of its own. Decaf, on your Mac, texts the flip phone when something can’t wait; the rest waits for when you sit down.
You answer in the same thread. Before a reply is relayed, Decaf asks for confirmation, and it goes out from your main number, as if you had typed it on your Mac. Your group chats stay where they are.
Decaf
Decaf works while the Mac is awake and online. You will be slower to reply than you were from an iPhone.
Decaf’s setup assumes your main number stays in your iPhone. Four things to decide before you call your carrier.
Already moved your main number to the flip phone? Then it isn’t in an iPhone any more, and Decaf has nothing to relay from.
Free 14-day trial. Then a $20 one-time purchase.
Join the waitlistSetting up takes about 10 minutes with both phones handy. The setup guide has every step.