Oh god... this is terrible.
How much power would that panel provide 500mW?
An inverter to main? Bam 80% efficiency so your looking at 400mW.
And then a buck converter to your device? Bam 80% efficiency so looking at 320mW.
Assuming the smallest smartphone battery... 3.7v nominal, 1300mAh, thats 4810mWh... 15 hours to charge provided the panel is in good light etc.
That isn't the only issue, they device itself isn't practical, you HAVE to stick it to a window or something, if you plug in a charger, no way in hell is it going to rest nicely on it's back to face the sun, and when it is on the window, it will probably be at a poor angle.
You can't say... have a flexible panel on the outside of a messenger bag and charge your phone that is inside or anything, it's dumb