You can purchase low-cost Rosco Neutral Density Filters for the light meter on your phone or tablet, here:
The set includes three different filters, ND.24, ND.38 and ND.65 set in a low-tack semi-transparent mounting. The filters can be used to reduce the light signal going into the light meter, on your phone or tablet, to allow it to achieve much higher readings than normal.
If the light meter on your Android smartphone or tablet is restricted by a low maximum reading, you can use these filters to greatly increase the range of the light meter (while running the Okapi Solar Calculator app, which automatically recalculates the light meter reading).
Customers in Canada and US:
Set of three Neutral Density Filters, only CA$5.50. Shipping, processing and applicable taxes included!
Set of three Neutral Density Filters, only CA$8.00 with International Shipping and processing included!