I use GIMP and it's comparable to most of the photo shops applications out there.
Start you day by eating protein and then eat several smaller meals throughout the day. Make sure to drink at least 8 glasses of water a day. The smaller meals over the course of day will help you metabolism shift to a higher gear. The water will help you flush out toxins which can stop the process.
Have your hormones checked you could hypothryoid. Weight gain is one many symptoms. If you are exercising and gaining weight it just simply be you are building muscle which weighs more that fat