Hello,
If you build DIY synths and MIDI gears, you certainly use various apps to send MIDI messages to test your projects.
A few months ago, I asked my nephew to design a web-based application to create custom midi interface. He ended with a super user-friendly app with which you can organise a complete MIDI controllers set in a few clicks !

Here are some of the features :
- a nice collection of MIDI components : slider, knob, buttons, drop down list, labels.
- customise MIDI components : controller number, input and output range, offset, name, color, size
- magnetic canevas to align nicely the components
- save and recall (.json files)
- bank of pre-made layouts
- "edit" and "run" mode

There are a lot of benefits of using a web-based app : no third-party software, no coding, you can share your interface, cross-platform...
It needs more development, but I think it is a really nice job that deserves a thumb up (my nephew is only 19). If you use this tool for your personal projects, consider the buy-him-a-coffee button ! And of course feedback will be very appreciated.

Here is the link :
<a href=" removed link " target="_blank" rel="noopener"> removed link

Emmanuel