ModbusClient 4+

It does work but the interface is not very intuitive and the icons are refresh icons not connect icons. Needs work. Not worth a subscription app.
Should have a server built in.
-NodeJS / BAS Programmer

Hi, can you please email your suggestions for a more intuitive UI to support@apphugs.com - We would be very happy to improve the interface and make the application more intuitive.

This app works very well for Modbus/IP. I suggest that the authors expand its capabilities to also support Modbus/RTU.

Thanks for the feedback, RTU master is now available: https://apps.apple.com/us/app/modbus-rtu-master/id1551561587

I will have to rate on the high side since they don't say what their product will do and it does about that. A hint, don't forget to offset your number by one. Only one number will be read at a time. This routine will send out the basic modbus commands. There is Onother product that will do more of what one actually wants. To request help, you have to join their online support and sign away your life's history away along with all your friends and acquaintances. I think this might be a front to force tekkies to join social media. The software is lean, clean and after much guessing does function as stated.

No more guessing needed, the latest version comes with a video:
https://youtu.be/oB1WdjlLuCk
No, this is not a front to join social media. The support forum is there to ensure answers to questions can be shared with all users.