Hi Alex,
The ArcGIS Pro design team uses a couple of tools for wireframing. Our go to tool is Figma. We use Figma for brainstorming new features, creating initial concepts and finally also making hi-fidelity wireframes. Another tool we frequently use is Balsamiq. This is simple and easy tool for wireframing but it is definitely not a tool for hi-fidelity designs. Another option that we do not use internally but is a good wireframing tool is "Lunacy". This is a free wireframing tool comparable to Sketch and Figma. This is a good tool to get started with.
We also use the following resources extensibly:
Hope this is helpful.
I know this is an old thread, but here is a a link to ESRI's ArcGIS Pro UI kit for Figma: https://www.figma.com/community/file/1525609637019504157
Hi @Gres thank you for posting this link!
The ArcGIS Pro SDK UI Kit for Figma was released Summer of 2025! If you have any feedback we actively iterating on improving the UI Kit. If there additional resources that we can provide also please let us know.
https://www.figma.com/community/file/1525609637019504157/arcgis-pro-ui-kit
I know this is an old thread, but here is a a link to ESRI's ArcGIS Pro UI kit for Figma: https://www.figma.com/community/file/1525609637019504157