PhoneLeash is a capable app with a broader feature set, including MMS, RCS, WhatsApp, and two-way reply. Its privacy policy also states that messages pass through its backend servers. Forwardit is narrower by design: it focuses on SMS forwarding to email or phone with no Forwardit server in the message path.
Get Forwardit — it's free“Messages pass through PhoneLeash's backend servers… The most recent message body for each device is briefly retained on its backend record.”
— PhoneLeash — Privacy PolicyForwardit matches and forwards SMS on the device. Your messages do not pass through Forwardit backend servers.
Forwardit is free to download and includes a working free tier, with Premium available when you need more filters and destinations.
On-device matching and user-controlled SMTP email forwarding mean Forwardit does not keep a backend record of your message content.
PhoneLeash is powerful if you need MMS, RCS, WhatsApp, or two-way reply. Forwardit is the better fit if your priority is private SMS forwarding to email or phone, without a cloud relay and with a free tier to start.