How can I avoid getting rid of the reflecion/sun spot when filming towards the sun as pic shows?

Any filter recommendations? App settings??

You could try using a Polarizer Filter. ND Filters are used for Lowering the Amount of Light entering the Sensor. You can also use a Combination of an ND + Polariser in 1 Filter.

Try Polar Pro, they are Top Class Filters.

This Kit is For Mavic / There is a Kit for the Spark / I own Both -

Have a Look Here -

Try Polar Pro Polariser filter. It would help reduce the glares from reflection and improve colour saturation.
Available from Amazon as a 3 filter set ( cheapest)