3 ideas- tiny lcd and uv sensor and cad file/printed box for the circuit.

[katysei]

 tiny lcd/eink/othertechnology  display for text/pics.
current displays in tiny form factor are hard to find.

uv sensor  that outputs uva/uvb index.

cad file for printed box/ or "real "plastic box for the circuit so you can package it nicely.
either sold or a file that you can set sizes for those who are to familiar with cad.

best regards

jossie.