Simmo

Simmo automatically chooses the best SIM for every call and helps you use the best SIM when you land in a new country.

And it uses Android's call routing functionality so it works hands free with your headphones, car, or AI assistant.

• Custom rules in case you have multiple SIMs for one country.
• Match single countries or whole groups (EU/EEA, North America, Caribbean +1).
• Choose to send calls to Google Voice or another calling app instead of a SIM.
• Data rules for travel — Simmo checks on arrival and warns when you're roaming or using the wrong SIM.
• If a rule needs an eSIM that's currently off, Simmo guides you to re-enable it.
• No surprises — if no rule matches, your call goes through on your default SIM exactly as it would have. Emergency calls are never touched.
• Private by design — rules and number parsing run entirely on your device. Simmo has no servers, and your dialed numbers are never sent to us.