Test version 0.2.0 is online offers the possibility to choose a device icon on pairing.
You can upload an own SVG icon or select a mdi icon from the list. The icons can be found/searched on https://materialdesignicons.com.
This functionality is taken from Harries MQTT Hub app - thanks for your support 
Example:
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Add a light:
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Icon selection:
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mdi icon selected:
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added device:
