The best alternatives to Termix are Panic, Proxy.app, and Secure ShellFish. If these 3 options don't work for you, we've listed a few more alternatives below.
What do you think of Termix?
Postman Recorder by DevTools— Export Postman APIs from browser
Secure ShellFish is a SSH and SFTP file manager that works well with other apps. Your server content is available in the Files app & other apps supporting the document browser or document picker.
Pisth is an open source SSH and SFTP client for iOS. Main Features: • Manage files in your SSH server and use the Shell in the same app. • Edit text files and code with colored syntax. • The terminal is like xterm, so you can use text editors such as nano, vim, etc. • SSH Keys • Open multiple panels in iPad. • Find servers with Bonjour.